Chapter 12.4
Wages, capital and the ZIP code vote
ZIP codes with more capital-gains returns swung more toward the Democrats between 2016 and 2020 and ZIP codes with more EITC returns swung less, but the capital-gains sign depends on the controls and the EITC link is near zero with poverty, college and race held fixed, and the definition of the ZIP-code college variable is unresolved.
DraftFigures and numbers may change as the analysis is rebuilt.what is still being checked
The ACS release behind the ZIP-code controls (poverty, college, Black and Hispanic shares) is not recorded in the demographic source file. The ZIP-code controls are to be rebuilt from a dated 5-year ACS release; the county results use dated controls and give the same conclusions for the EITC share. The ZIP-code college variable has no resolved definition (some college or more, or degrees), so every ZIP-code result that holds it fixed is conditional on that coding.
ZIP codes in the highest decile of the share of returns that claim the earned income tax credit (EITC) swung 5.25.2 points of two-party margin swing, toward the RepublicansEstimandvote-weighted mean swing of the decile, shown as a size (95% interval clustered on county)Interval95% CI 3.5 to 6.9n2,715Weightsvotes cast in the ZIP code in 2020 (pres_tot_2020)PopulationZIP codes in decile 10 of the share of returns claiming the earned income tax creditPeriod2016 to 2020SourcePrecinct votes on census geographies points toward the Republicans between 2016 and 2020, and ZIP codes in the highest decile of the share of returns that report a capital gain swung 5.45.4 points of two-party margin swing, toward the DemocratsEstimandvote-weighted mean swing of the decile, shown as a size (95% interval clustered on county)Interval95% CI 4.4 to 6.4n2,715Weightsvotes cast in the ZIP code in 2020 (pres_tot_2020)PopulationZIP codes in decile 10 of the share of returns reporting a net capital gainPeriod2016 to 2020SourcePrecinct votes on census geographies points toward the Democrats. The coefficient of the swing on the capital-gains share, in points of margin per standard deviationStandard deviationA measure of how far values typically fall from their average. A larger standard deviation means the values are more spread out. of the share, is +2.4 (95% CI 2.0 to 2.9)+2.4 points of swing in the two-party margin per standard deviation of the measure (positive is toward the Democrats)Estimandweighted least squares coefficient of the share of returns reporting a net capital gain, with no controls (95% interval clustered on county)Interval95% CI 2.0 to 2.9n27,144Weightsvotes cast in the ZIP code in 2020 (pres_tot_2020)PopulationZIP code tabulation areas in the contiguous states with more than 100 votes in 2020 and complete IRS and ACS measuresPeriod2016 to 2020 swing; IRS tax year 2022; ACS 5-year estimatesSourcePrecinct votes on census geographies with no controls and −1.0 (95% CI −1.6 to −0.4)−1.0 points of swing in the two-party margin per standard deviation of the measure (positive is toward the Democrats)Estimandweighted least squares coefficient of the share of returns reporting a net capital gain, net of the college share (95% interval clustered on county)Interval95% CI −1.6 to −0.4n27,144Weightsvotes cast in the ZIP code in 2020 (pres_tot_2020)PopulationZIP code tabulation areas in the contiguous states with more than 100 votes in 2020 and complete IRS and ACS measuresPeriod2016 to 2020 swing; IRS tax year 2022; ACS 5-year estimatesSourcePrecinct votes on census geographies with the college share held fixed. To hold the college share fixed is to compare ZIP codes with similar college shares.A coefficient here is the difference in swing, in points of margin, between ZIP codes one standard deviation apart on the measure. One standard deviation is 11.511.5 percentage points of returnsEstimandvote-weighted standard deviation of the capital-gains shareWeightsvotes cast in the ZIP code in 2020 (pres_tot_2020)PopulationZIP code tabulation areas in the contiguous states with more than 100 votes in 2020 and complete IRS and ACS measuresPeriodIRS tax year 2022SourceIRS SOI ZIP code data points of share for capital gains and 8.38.3 percentage points of returnsEstimandvote-weighted standard deviation of the EITC shareWeightsvotes cast in the ZIP code in 2020 (pres_tot_2020)PopulationZIP code tabulation areas in the contiguous states with more than 100 votes in 2020 and complete IRS and ACS measuresPeriodIRS tax year 2022SourceIRS SOI ZIP code data for the EITC. The EITC coefficient goes from −3.5 (95% CI −4.0 to −3.0)−3.5 points of swing in the two-party margin per standard deviation of the measure (positive is toward the Democrats)Estimandweighted least squares coefficient of the share of returns claiming the earned income tax credit, with no controls (95% interval clustered on county)Interval95% CI −4.0 to −3.0n27,144Weightsvotes cast in the ZIP code in 2020 (pres_tot_2020)PopulationZIP code tabulation areas in the contiguous states with more than 100 votes in 2020 and complete IRS and ACS measuresPeriod2016 to 2020 swing; IRS tax year 2022; ACS 5-year estimatesSourcePrecinct votes on census geographies with no controls to +0.3 (95% CI −0.8 to 1.4)+0.3 points of swing in the two-party margin per standard deviation of the measure (positive is toward the Democrats)Estimandweighted least squares coefficient of the share of returns claiming the earned income tax credit, net of the poverty rate, college share, Black share and Hispanic share (95% interval clustered on county)Interval95% CI −0.8 to 1.4n27,144Weightsvotes cast in the ZIP code in 2020 (pres_tot_2020)PopulationZIP code tabulation areas in the contiguous states with more than 100 votes in 2020 and complete IRS and ACS measuresPeriod2016 to 2020 swing; IRS tax year 2022; ACS 5-year estimatesSourcePrecinct votes on census geographies with poverty, college, Black and Hispanic shares held fixed, a set that leaves out the average tax rate. The capital-gains share correlatesCorrelationA number from minus 1 to plus 1 for how closely two measures move together in a straight-line pattern. Zero means no straight-line pattern; a correlation does not say that one measure causes the other. +0.81 (95% CI 0.79 to 0.82)+0.81 correlation coefficient, from −1 to +1Estimandcorrelation of the capital-gains share with the college share (the ZIP-code college variable, whose definition is unresolved) (vote-weighted; 95% interval from a bootstrap of counties, 2,000 replicates)Interval95% CI 0.79 to 0.82n27,144Weightsvotes cast in the ZIP code in 2020 (pres_tot_2020)PopulationZIP code tabulation areas in the contiguous states with more than 100 votes in 2020 and complete IRS and ACS measuresPeriod2016 to 2020 swing; IRS tax year 2022; ACS 5-year estimatesSourcePrecinct votes on census geographies with the college share, so these data cannot separate the two.
The unit is the ZIP code tabulation areaZCTAZIP Code Tabulation Area: the Census Bureau's area approximation of a ZIP code, built from the census blocks that fall inside it. It is the one neighborhood geography that lines up between the 2016 and 2020 vote estimates., the census approximation of a ZIP code, and not the county. The sample is 27,14427,144 ZIP code tabulation areasEstimandcount of ZCTAs in the analysis sampleWeightsnone (count)PopulationZIP code tabulation areas in the contiguous states with more than 100 votes in 2020 and complete IRS and ACS measuresPeriod2016 and 2020SourcePrecinct votes on census geographies ZIP codes in 3,0883,088 countiesEstimandcount of county codes clustered onWeightsnone (count)Populationcounties that contain at least one ZCTA of the analysis samplePeriod2016 and 2020SourcePrecinct votes on census geographies counties, and the county analysis uses 3,0803,080 countiesEstimandcount of counties in the county sampleWeightsnone (count)Populationcounties in the contiguous states with ZIP-code shares and county demographicsPeriod2016 to 2020 swing; IRS tax year 2022; county demographics centred on 2020SourceCounty election returns counties; Figure 8 in the last section lists the exclusions. The EITC share stands in for low wages, as the next section explains. Counties enter in two ways: as the clusters that set the width of the ZIP-code intervals, and as a second grain in which ZIP-code shares are averaged to counties and compared with certified county returns. Unless the text says otherwise, ZIP-code statistics weight each ZIP code by its 2020 votes and county statistics weight each county by its 2020 two-party votes.
What the shares and the swing measure
The earned income tax credit is a refundable federal credit for households with low earnings from work, so the share of a ZIP code's returns that claim it is higher where more filers have low earnings; it also depends on children in the household and on take-up. A capital gain is the profit from selling an asset such as stock or a home, and returns also report gains that funds distribute, so the share of returns that report one is higher where more households hold assets that produce gains. Both shares come from IRS Statistics of Income data for tax year 2022, and both describe filers: households that do not file a return are absent. The vote-weighted mean is 14.2%14.2% percent of returnsEstimandvote-weighted mean of the EITC shareWeightsvotes cast in the ZIP code in 2020 (pres_tot_2020)PopulationZIP code tabulation areas in the contiguous states with more than 100 votes in 2020 and complete IRS and ACS measuresPeriodIRS tax year 2022SourceIRS SOI ZIP code data of returns for the EITC and 20.1%20.1% percent of returnsEstimandvote-weighted mean of the capital-gains shareWeightsvotes cast in the ZIP code in 2020 (pres_tot_2020)PopulationZIP code tabulation areas in the contiguous states with more than 100 votes in 2020 and complete IRS and ACS measuresPeriodIRS tax year 2022SourceIRS SOI ZIP code data for capital gains, and across ZIP codes the two shares correlate −0.78 (95% CI −0.79 to −0.77)−0.78 correlation coefficient, from −1 to +1Estimandcorrelation of the capital-gains share with the EITC share (vote-weighted; 95% interval from a bootstrap of counties, 2,000 replicates)Interval95% CI −0.79 to −0.77n27,144Weightsvotes cast in the ZIP code in 2020 (pres_tot_2020)PopulationZIP code tabulation areas in the contiguous states with more than 100 votes in 2020 and complete IRS and ACS measuresPeriod2016 to 2020 swing; IRS tax year 2022; ACS 5-year estimatesSourcePrecinct votes on census geographies (−0.68−0.68 correlation coefficient, from −1 to +1Estimandcorrelation of the capital-gains share with the EITC share, every ZIP code counted equally (95% interval from a bootstrap of counties, 2,000 replicates)Interval95% CI −0.70 to −0.67n27,144Weightsnone (every ZIP code counted equally)PopulationZIP code tabulation areas in the contiguous states with more than 100 votes in 2020 and complete IRS and ACS measuresPeriod2016 to 2020 swing; IRS tax year 2022; ACS 5-year estimatesSourcePrecinct votes on census geographies with each ZIP code counted equally), so a ZIP code with many EITC claims has few capital-gains returns and the reverse.The IRS shares are for tax year 2022, which follows both elections they are set against. The ZIP-code demographic file that carries the poverty, college and race controls does not record which American Community Survey release it uses, so those controls are undated. The county controls come from a panel with documented anchor years. The last section returns to the timing.
Votes for 2016 and 2020 are precinct returns that Fekrazad allocated to ZIP code tabulation areas in proportion to household population [1], from the Voting and Election Science Team's 2016 precinct returns [2] and the 2020 returns of the MIT Election Data and Science Lab [3]. The outcome is the swingSwingThe change in a place's two-party margin between two elections. In this book a positive swing is a move toward the Democrats.: the 2020 two-party margin minus the 2016 margin, Democratic minus Republican, in pointsPercentage pointThe unit for the difference between two percentages. A change from one share to another is stated in points, not in percent, so that absolute and relative change are not confused., so a positive swing is toward the Democrats. Across the ZIP codes in this chapter the vote-weighted mean of the swing is 3.03.0 points of two-party margin (Democratic minus Republican)Estimandvote-weighted mean of the ZIP-code swing (2020 margin minus 2016 margin)Weightsvotes cast in the ZIP code in 2020 (pres_tot_2020)PopulationZIP code tabulation areas in the contiguous states with more than 100 votes in 2020 and complete IRS and ACS measuresPeriod2016 to 2020SourcePrecinct votes on census geographies points toward the Democrats.The mean weights both years' margins of a ZIP code by its 2020 votes. The aggregate two-party margin of the same ZIP codes weights each year by that year's votes and moved 2.32.3 points of two-party margin (Democratic minus Republican)Estimandchange in the aggregate two-party margin of the ZIP codes in the analysis sample, toward the DemocratsWeightsnone (count)PopulationZIP code tabulation areas in the contiguous states with more than 100 votes in 2020 and complete IRS and ACS measuresPeriod2016 to 2020SourcePrecinct votes on census geographies points, from +2.3+2.3 points of two-party margin (Democratic minus Republican)Estimandtwo-party margin of the aggregate votes of the ZIP codes in the analysis sample (each year weighted by that year's votes)Weightsnone (count)PopulationZIP code tabulation areas in the contiguous states with more than 100 votes in 2020 and complete IRS and ACS measuresPeriod2016SourcePrecinct votes on census geographies to +4.6+4.6 points of two-party margin (Democratic minus Republican)Estimandtwo-party margin of the aggregate votes of the ZIP codes in the analysis sample (each year weighted by that year's votes)Weightsnone (count)PopulationZIP code tabulation areas in the contiguous states with more than 100 votes in 2020 and complete IRS and ACS measuresPeriod2020SourcePrecinct votes on census geographies.
Swing rose with capital gains and fell with EITC
Figure 1 ranks the ZIP code tabulation areas by each share and splits them into ten equal groups, or deciles. The mean swing is 7.2 (95% CI 5.6 to 8.8)7.2 points of two-party margin swing, toward the RepublicansEstimandvote-weighted mean swing of the decile, shown as a size (95% interval clustered on county)Interval95% CI 5.6 to 8.8n2,715Weightsvotes cast in the ZIP code in 2020 (pres_tot_2020)PopulationZIP codes in decile 1 of the share of returns reporting a net capital gainPeriod2016 to 2020SourcePrecinct votes on census geographies points toward the Republicans in the lowest capital-gains decile and 5.4 (95% CI 4.4 to 6.4)5.4 points of two-party margin swing, toward the DemocratsEstimandvote-weighted mean swing of the decile, shown as a size (95% interval clustered on county)Interval95% CI 4.4 to 6.4n2,715Weightsvotes cast in the ZIP code in 2020 (pres_tot_2020)PopulationZIP codes in decile 10 of the share of returns reporting a net capital gainPeriod2016 to 2020SourcePrecinct votes on census geographies points toward the Democrats in the highest, and it is 6.3 (95% CI 5.5 to 7.2)6.3 points of two-party margin swing, toward the DemocratsEstimandvote-weighted mean swing of the decile, shown as a size (95% interval clustered on county)Interval95% CI 5.5 to 7.2n2,715Weightsvotes cast in the ZIP code in 2020 (pres_tot_2020)PopulationZIP codes in decile 1 of the share of returns claiming the earned income tax creditPeriod2016 to 2020SourcePrecinct votes on census geographies points toward the Democrats in the lowest EITC decile and 5.2 (95% CI 3.5 to 6.9)5.2 points of two-party margin swing, toward the RepublicansEstimandvote-weighted mean swing of the decile, shown as a size (95% interval clustered on county)Interval95% CI 3.5 to 6.9n2,715Weightsvotes cast in the ZIP code in 2020 (pres_tot_2020)PopulationZIP codes in decile 10 of the share of returns claiming the earned income tax creditPeriod2016 to 2020SourcePrecinct votes on census geographies points toward the Republicans in the highest. Most deciles of both shares swung toward the Democrats, as the mean of all ZIP codes did, so the ordering is one of how far the deciles moved. Intervals use clustered standard errorsClustered standard errorsStandard errors that allow answers within the same group, such as the same county or the same week, to be related. They are wider than ordinary errors when members of a group resemble each other. at the county, because ZIP codes in one county share local conditions and are not independent draws.
Figure 2 plots the 2020 margin for the same deciles. It bends into a U for both shares: the margin was most Democratic in the lowest and highest deciles and lowest in the middle of the range.
Figure 2
The 2020 margin was most Democratic at both ends of each share and lowest in the middle of the range
Vote-weighted mean 2020 two-party margin, Democratic minus Republican, by decile of ZIP codes ranked by share of returns; 95% intervals clustered on county
Democratic minus Republican margin, 2020 (points)
Show data
| Share ranked | Decile | Mean margin, 2020 (points) | Lower bound | Upper bound | ZIP codes |
|---|---|---|---|---|---|
| Capital-gains share | 1 | +48.4 | +42.5 | +54.3 | 2,715 |
| Capital-gains share | 2 | +14.0 | +8.8 | +19.2 | 2,714 |
| Capital-gains share | 3 | −4.8 | −9.6 | 0.0 | 2,714 |
| Capital-gains share | 4 | −11.6 | −15.7 | −7.6 | 2,715 |
| Capital-gains share | 5 | −12.0 | −15.2 | −8.9 | 2,714 |
| Capital-gains share | 6 | −6.9 | −10.3 | −3.4 | 2,714 |
| Capital-gains share | 7 | −6.9 | −10.2 | −3.6 | 2,715 |
| Capital-gains share | 8 | +0.8 | −2.7 | +4.3 | 2,714 |
| Capital-gains share | 9 | +5.6 | +2.1 | +9.0 | 2,714 |
| Capital-gains share | 10 | +22.6 | +17.3 | +27.9 | 2,715 |
| EITC share | 1 | +19.9 | +13.5 | +26.4 | 2,715 |
| EITC share | 2 | +9.5 | +5.7 | +13.4 | 2,714 |
| EITC share | 3 | +2.5 | −1.2 | +6.2 | 2,714 |
| EITC share | 4 | −0.8 | −4.8 | +3.1 | 2,715 |
| EITC share | 5 | −6.0 | −9.6 | −2.5 | 2,714 |
| EITC share | 6 | −6.3 | −10.5 | −2.0 | 2,714 |
| EITC share | 7 | −6.1 | −11.9 | −0.2 | 2,715 |
| EITC share | 8 | −3.7 | −9.1 | +1.8 | 2,714 |
| EITC share | 9 | +3.4 | −3.0 | +9.9 | 2,714 |
| EITC share | 10 | +33.3 | +27.3 | +39.2 | 2,715 |
The two ends of each U are different kinds of places (Figure 3). The lowest capital-gains decile and the highest EITC decile are poor ZIP codes with large Black and Hispanic populations, and they are the two end deciles that swung toward the Republicans. The other two ends, the highest capital-gains decile and the lowest EITC decile, are college-heavy. A ZIP code can be solidly Democratic in level and still have moved toward the Republicans, so the swing orders the deciles from one end of a share to the other while the level is high at both ends.
Figure 3
The two end deciles that swung toward the Republicans are the poorest of the four
Vote-weighted mean swing, 2020 margin and demographic profile of the lowest and highest deciles of each share; positive swing and margin are toward the Democrats
| ZIP codes in the | Swing, 2016 to 2020 (points) | Margin, 2020 (points) | Black and Hispanic share (%) | Poverty rate (%) | ZIP-code college variable (%) |
|---|---|---|---|---|---|
| Lowest capital-gains decile | −7.2 | +48.4 | 76.5 | 23.4 | 40.6 |
| Highest capital-gains decile | +5.4 | +22.6 | 12.8 | 3.8 | 82.1 |
| Lowest EITC decile | +6.3 | +19.9 | 8.5 | 2.7 | 82.9 |
| Highest EITC decile | −5.2 | +33.3 | 66.8 | 22.9 | 43.9 |
Show data
| ZIP codes in the | Swing (points) | Lower bound | Upper bound | Margin, 2020 (points) | Lower bound | Upper bound | Black and Hispanic share (%) | Lower bound | Upper bound | Poverty rate (%) | Lower bound | Upper bound | ZIP-code college variable (%) | Lower bound | Upper bound | ZIP codes |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Lowest capital-gains decile | −7.2 | −8.8 | −5.6 | +48.4 | +42.5 | +54.3 | 76.5 | 72.8 | 80.2 | 23.4 | 22.4 | 24.4 | 40.6 | 38.9 | 42.3 | 2,715 |
| Highest capital-gains decile | +5.4 | +4.4 | +6.4 | +22.6 | +17.3 | +27.9 | 12.8 | 11.7 | 13.8 | 3.8 | 3.6 | 4.0 | 82.1 | 81.3 | 82.8 | 2,715 |
| Lowest EITC decile | +6.3 | +5.5 | +7.2 | +19.9 | +13.5 | +26.4 | 8.5 | 7.9 | 9.1 | 2.7 | 2.6 | 2.8 | 82.9 | 81.8 | 83.9 | 2,715 |
| Highest EITC decile | −5.2 | −6.9 | −3.5 | +33.3 | +27.3 | +39.2 | 66.8 | 63.2 | 70.5 | 22.9 | 22.2 | 23.7 | 43.9 | 42.9 | 45.0 | 2,715 |
Holding college fixed reverses the capital-gains sign
In these data a ZIP code's college share is the college variable of the ZIP-code demographic file, and what that variable counts is unresolved.The file describes the variable as the percentage of the population with a college degree or higher and names no table, age group or release. Aggregated to counties it averages 52.7%52.7% percent (share counted by the ZIP-code college variable, definition unresolved)Estimandmean across counties of the vote-weighted mean of the ZIP-code college variablen3,080Weightsvotes cast in the ZIP code in 2020 (pres_tot_2020)Populationcounties in the county samplePeriodACS 5-year estimates, ZIP codes averaged to countiesSourcePrecinct votes on census geographies against 23.6%23.6% percent of adultsEstimandmean across counties of the bachelor's sharen3,080Weightsnone (full counts and interpolated estimates)Populationcounties in the county samplePeriodcounty demographics centred on 2020SourceCounty demographics panel for the county bachelor's share, with a correlation of +0.86+0.86 correlation coefficient, from −1 to +1Estimandcorrelation across counties of the ZIP-derived college variable with the bachelor's sharen3,080Weightsnone (each county counted once)Populationcounties in the county samplePeriodACS 5-year estimatesSourcePrecinct votes on census geographies, so its level is far above a bachelor's share. The level and the correlation do not establish whether it counts some college or more or degrees only, so every result below that holds it fixed is conditional on that coding. The county analysis uses the bachelor's share. It correlates +0.81 (95% CI 0.79 to 0.82)+0.81 correlation coefficient, from −1 to +1Estimandcorrelation of the capital-gains share with the college share (the ZIP-code college variable, whose definition is unresolved) (vote-weighted; 95% interval from a bootstrap of counties, 2,000 replicates)Interval95% CI 0.79 to 0.82n27,144Weightsvotes cast in the ZIP code in 2020 (pres_tot_2020)PopulationZIP code tabulation areas in the contiguous states with more than 100 votes in 2020 and complete IRS and ACS measuresPeriod2016 to 2020 swing; IRS tax year 2022; ACS 5-year estimatesSourcePrecinct votes on census geographies with the capital-gains share and +0.47 (95% CI 0.43 to 0.51)+0.47 correlation coefficient, from −1 to +1Estimandcorrelation of the college share with the 2016 to 2020 swing (vote-weighted; 95% interval from a bootstrap of counties, 2,000 replicates)Interval95% CI 0.43 to 0.51n27,144Weightsvotes cast in the ZIP code in 2020 (pres_tot_2020)PopulationZIP code tabulation areas in the contiguous states with more than 100 votes in 2020 and complete IRS and ACS measuresPeriod2016 to 2020 swing; IRS tax year 2022; ACS 5-year estimatesSourcePrecinct votes on census geographies with the swing (+0.44+0.44 correlation coefficient, from −1 to +1Estimandcorrelation of the college share with the 2016 to 2020 swing, every ZIP code counted equally (95% interval from a bootstrap of counties, 2,000 replicates)Interval95% CI 0.41 to 0.47n27,144Weightsnone (every ZIP code counted equally)PopulationZIP code tabulation areas in the contiguous states with more than 100 votes in 2020 and complete IRS and ACS measuresPeriod2016 to 2020 swing; IRS tax year 2022; ACS 5-year estimatesSourcePrecinct votes on census geographies with each ZIP code counted equally). A standard deviation of the college share goes with +3.4 (95% CI 3.1 to 3.8)+3.4 points of swing in the two-party margin per standard deviation of the measure (positive is toward the Democrats)Estimandweighted least squares coefficient of the college share with no controls (95% interval clustered on county)Interval95% CI 3.1 to 3.8n27,144Weightsvotes cast in the ZIP code in 2020 (pres_tot_2020)PopulationZIP code tabulation areas in the contiguous states with more than 100 votes in 2020 and complete IRS and ACS measuresPeriod2016 to 2020 swing; IRS tax year 2022; ACS 5-year estimatesSourcePrecinct votes on census geographies points of swing, against +2.4 (95% CI 2.0 to 2.9)+2.4 points of swing in the two-party margin per standard deviation of the measure (positive is toward the Democrats)Estimandweighted least squares coefficient of the share of returns reporting a net capital gain, with no controls (95% interval clustered on county)Interval95% CI 2.0 to 2.9n27,144Weightsvotes cast in the ZIP code in 2020 (pres_tot_2020)PopulationZIP code tabulation areas in the contiguous states with more than 100 votes in 2020 and complete IRS and ACS measuresPeriod2016 to 2020 swing; IRS tax year 2022; ACS 5-year estimatesSourcePrecinct votes on census geographies for a standard deviation of the capital-gains share.
Figure 4 adds controls to each share one set at a time, as separate models on the same 27,14427,144 ZIP code tabulation areasEstimandcount of ZCTAs in the analysis sampleWeightsnone (count)PopulationZIP code tabulation areas in the contiguous states with more than 100 votes in 2020 and complete IRS and ACS measuresPeriod2016 and 2020SourcePrecinct votes on census geographies ZIP codes. With the college share held fixed (third row), the capital-gains coefficient goes from +2.4 (95% CI 2.0 to 2.9)+2.4 points of swing in the two-party margin per standard deviation of the measure (positive is toward the Democrats)Estimandweighted least squares coefficient of the share of returns reporting a net capital gain, with no controls (95% interval clustered on county)Interval95% CI 2.0 to 2.9n27,144Weightsvotes cast in the ZIP code in 2020 (pres_tot_2020)PopulationZIP code tabulation areas in the contiguous states with more than 100 votes in 2020 and complete IRS and ACS measuresPeriod2016 to 2020 swing; IRS tax year 2022; ACS 5-year estimatesSourcePrecinct votes on census geographies with no controls to −1.0 (95% CI −1.6 to −0.4)−1.0 points of swing in the two-party margin per standard deviation of the measure (positive is toward the Democrats)Estimandweighted least squares coefficient of the share of returns reporting a net capital gain, net of the college share (95% interval clustered on county)Interval95% CI −1.6 to −0.4n27,144Weightsvotes cast in the ZIP code in 2020 (pres_tot_2020)PopulationZIP code tabulation areas in the contiguous states with more than 100 votes in 2020 and complete IRS and ACS measuresPeriod2016 to 2020 swing; IRS tax year 2022; ACS 5-year estimatesSourcePrecinct votes on census geographies. Holding the poverty rate fixed instead brings it to +0.3 (95% CI −0.1 to 0.7)+0.3 points of swing in the two-party margin per standard deviation of the measure (positive is toward the Democrats)Estimandweighted least squares coefficient of the share of returns reporting a net capital gain, net of the poverty rate (95% interval clustered on county)Interval95% CI −0.1 to 0.7n27,144Weightsvotes cast in the ZIP code in 2020 (pres_tot_2020)PopulationZIP code tabulation areas in the contiguous states with more than 100 votes in 2020 and complete IRS and ACS measuresPeriod2016 to 2020 swing; IRS tax year 2022; ACS 5-year estimatesSourcePrecinct votes on census geographies, so most of the raw capital-gains association is shared with low poverty as well as with college. With intervals clustered on state (4949 states and the District of ColumbiaEstimandcount of state clusters in the state-clustered ZIP-code modelsWeightsnone (count)Populationstates and the District of Columbia with a ZIP code in the analysis samplePeriod2016 and 2020SourcePrecinct votes on census geographies clusters) instead of county, the capital-gains intervals with the college share held fixed, alone (−1.0 (95% CI −2.1 to 0.0)−1.0 points of swing in the two-party margin per standard deviation of the measure (positive is toward the Democrats)Estimandweighted least squares coefficient of the share of returns reporting a net capital gain, net of the college share (95% interval clustered on state, 49 clusters)Interval95% CI −2.1 to 0.0n27,144Weightsvotes cast in the ZIP code in 2020 (pres_tot_2020)PopulationZIP code tabulation areas in the contiguous states with more than 100 votes in 2020 and complete IRS and ACS measuresPeriod2016 to 2020 swing; IRS tax year 2022; ACS 5-year estimatesSourcePrecinct votes on census geographies) or with the average tax rate (+1.4 (95% CI −0.3 to 3.0)+1.4 points of swing in the two-party margin per standard deviation of the measure (positive is toward the Democrats)Estimandweighted least squares coefficient of the share of returns reporting a net capital gain, net of the average tax rate and the college share (95% interval clustered on state, 49 clusters)Interval95% CI −0.3 to 3.0n27,144Weightsvotes cast in the ZIP code in 2020 (pres_tot_2020)PopulationZIP code tabulation areas in the contiguous states with more than 100 votes in 2020 and complete IRS and ACS measuresPeriod2016 to 2020 swing; IRS tax year 2022; ACS 5-year estimatesSourcePrecinct votes on census geographies), include zero, and every other interval in the ladder keeps its position relative to zero. The same check on the deciles leaves the intervals of the four end deciles away from zero.
Figure 4
Controls take the EITC coefficient to about zero and change the sign of the capital-gains coefficient
Weighted regression coefficient of the 2016 to 2020 swing on the share of returns, one set of controls per row; 95% intervals clustered on county in the first view and on state in the second
EITC share
Capital-gains share
Points of swing per standard deviation of the share (positive is toward the Democrats)
Show data
| Share | Controls | Coefficient | Lower bound, county clusters | Upper bound, county clusters | Interval, county clusters | Lower bound, state clusters | Upper bound, state clusters | Interval, state clusters | Partial correlation | Lower bound | Upper bound | ZIP codes | County clusters | State clusters |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| EITC share | No controls | −3.48 | −4.01 | −2.96 | Below zero | −4.31 | −2.65 | Below zero | −0.475 | −0.520 | −0.431 | 27,144 | 3,088 | 49 |
| EITC share | Poverty rate | −1.69 | −2.73 | −0.65 | Below zero | −3.35 | −0.03 | Below zero | −0.140 | −0.221 | −0.068 | 27,144 | 3,088 | 49 |
| EITC share | Average tax rate | −4.12 | −5.00 | −3.23 | Below zero | −5.50 | −2.74 | Below zero | −0.428 | −0.488 | −0.371 | 27,144 | 3,088 | 49 |
| EITC share | College share | −2.08 | −2.86 | −1.30 | Below zero | −3.38 | −0.78 | Below zero | −0.222 | −0.289 | −0.158 | 27,144 | 3,088 | 49 |
| EITC share | Average tax rate and college share | −2.76 | −3.58 | −1.93 | Below zero | −4.10 | −1.41 | Below zero | −0.290 | −0.356 | −0.229 | 27,144 | 3,088 | 49 |
| EITC share | Poverty, college, Black and Hispanic shares | +0.32 | −0.76 | +1.39 | Includes zero | −1.24 | +1.87 | Includes zero | +0.021 | −0.051 | +0.085 | 27,144 | 3,088 | 49 |
| Capital-gains share | No controls | +2.42 | +1.98 | +2.86 | Above zero | +1.84 | +3.00 | Above zero | +0.330 | +0.288 | +0.376 | 27,144 | 3,088 | 49 |
| Capital-gains share | Poverty rate | +0.31 | −0.09 | +0.71 | Includes zero | −0.23 | +0.85 | Includes zero | +0.038 | −0.006 | +0.087 | 27,144 | 3,088 | 49 |
| Capital-gains share | Average tax rate | +4.05 | +2.59 | +5.51 | Above zero | +2.58 | +5.51 | Above zero | +0.249 | +0.181 | +0.314 | 27,144 | 3,088 | 49 |
| Capital-gains share | College share | −1.02 | −1.61 | −0.43 | Below zero | −2.08 | +0.03 | Includes zero | −0.093 | −0.145 | −0.038 | 27,144 | 3,088 | 49 |
| Capital-gains share | Average tax rate and college share | +1.38 | +0.13 | +2.62 | Above zero | −0.26 | +3.02 | Includes zero | +0.087 | +0.017 | +0.155 | 27,144 | 3,088 | 49 |
| Capital-gains share | Poverty, college, Black and Hispanic shares | −2.74 | −3.22 | −2.26 | Below zero | −3.49 | −2.00 | Below zero | −0.258 | −0.296 | −0.214 | 27,144 | 3,088 | 49 |
The negative sign with the college share held fixed does not show a Republican lean among capital-gains filers. The capital-gains share and the college share correlate +0.81+0.81 correlation coefficient, from −1 to +1Estimandcorrelation of the capital-gains share with the college share (the ZIP-code college variable, whose definition is unresolved) (vote-weighted; 95% interval from a bootstrap of counties, 2,000 replicates)Interval95% CI 0.79 to 0.82n27,144Weightsvotes cast in the ZIP code in 2020 (pres_tot_2020)PopulationZIP code tabulation areas in the contiguous states with more than 100 votes in 2020 and complete IRS and ACS measuresPeriod2016 to 2020 swing; IRS tax year 2022; ACS 5-year estimatesSourcePrecinct votes on census geographies, so the regression has little independent variation in the capital-gains share to work with, and the sign depends on which other controls are present: with the average tax rate and the college share held fixed together the coefficient is +1.4 (95% CI 0.1 to 2.6)+1.4 points of swing in the two-party margin per standard deviation of the measure (positive is toward the Democrats)Estimandweighted least squares coefficient of the share of returns reporting a net capital gain, net of the average tax rate and the college share (95% interval clustered on county)Interval95% CI 0.1 to 2.6n27,144Weightsvotes cast in the ZIP code in 2020 (pres_tot_2020)PopulationZIP code tabulation areas in the contiguous states with more than 100 votes in 2020 and complete IRS and ACS measuresPeriod2016 to 2020 swing; IRS tax year 2022; ACS 5-year estimatesSourcePrecinct votes on census geographies. Work on Western democracies from 1948 to 2020 found that higher-educated voters had moved toward parties of the left while high-income voters continued to vote for the right [4], which is consistent with an education pattern in the ZIP-code swing, although that work describes individual voters and these data describe ZIP codes.
The EITC link is near zero with poverty, college and race fixed
The EITC coefficient in Figure 4 is −3.5 (95% CI −4.0 to −3.0)−3.5 points of swing in the two-party margin per standard deviation of the measure (positive is toward the Democrats)Estimandweighted least squares coefficient of the share of returns claiming the earned income tax credit, with no controls (95% interval clustered on county)Interval95% CI −4.0 to −3.0n27,144Weightsvotes cast in the ZIP code in 2020 (pres_tot_2020)PopulationZIP code tabulation areas in the contiguous states with more than 100 votes in 2020 and complete IRS and ACS measuresPeriod2016 to 2020 swing; IRS tax year 2022; ACS 5-year estimatesSourcePrecinct votes on census geographies with no controls. It is −1.7 (95% CI −2.7 to −0.6)−1.7 points of swing in the two-party margin per standard deviation of the measure (positive is toward the Democrats)Estimandweighted least squares coefficient of the share of returns claiming the earned income tax credit, net of the poverty rate (95% interval clustered on county)Interval95% CI −2.7 to −0.6n27,144Weightsvotes cast in the ZIP code in 2020 (pres_tot_2020)PopulationZIP code tabulation areas in the contiguous states with more than 100 votes in 2020 and complete IRS and ACS measuresPeriod2016 to 2020 swing; IRS tax year 2022; ACS 5-year estimatesSourcePrecinct votes on census geographies with the poverty rate held fixed, −2.1 (95% CI −2.9 to −1.3)−2.1 points of swing in the two-party margin per standard deviation of the measure (positive is toward the Democrats)Estimandweighted least squares coefficient of the share of returns claiming the earned income tax credit, net of the college share (95% interval clustered on county)Interval95% CI −2.9 to −1.3n27,144Weightsvotes cast in the ZIP code in 2020 (pres_tot_2020)PopulationZIP code tabulation areas in the contiguous states with more than 100 votes in 2020 and complete IRS and ACS measuresPeriod2016 to 2020 swing; IRS tax year 2022; ACS 5-year estimatesSourcePrecinct votes on census geographies with the college share held fixed and −2.8 (95% CI −3.6 to −1.9)−2.8 points of swing in the two-party margin per standard deviation of the measure (positive is toward the Democrats)Estimandweighted least squares coefficient of the share of returns claiming the earned income tax credit, net of the average tax rate and the college share (95% interval clustered on county)Interval95% CI −3.6 to −1.9n27,144Weightsvotes cast in the ZIP code in 2020 (pres_tot_2020)PopulationZIP code tabulation areas in the contiguous states with more than 100 votes in 2020 and complete IRS and ACS measuresPeriod2016 to 2020 swing; IRS tax year 2022; ACS 5-year estimatesSourcePrecinct votes on census geographies with the average tax rate and college share held fixed together. With the poverty rate, college share, Black share and Hispanic share all held fixed, a set that does not include the tax rate, it is +0.3 (95% CI −0.8 to 1.4)+0.3 points of swing in the two-party margin per standard deviation of the measure (positive is toward the Democrats)Estimandweighted least squares coefficient of the share of returns claiming the earned income tax credit, net of the poverty rate, college share, Black share and Hispanic share (95% interval clustered on county)Interval95% CI −0.8 to 1.4n27,144Weightsvotes cast in the ZIP code in 2020 (pres_tot_2020)PopulationZIP code tabulation areas in the contiguous states with more than 100 votes in 2020 and complete IRS and ACS measuresPeriod2016 to 2020 swing; IRS tax year 2022; ACS 5-year estimatesSourcePrecinct votes on census geographies, an interval that includes zero under both clusterings (+0.3 (95% CI −1.2 to 1.9)+0.3 points of swing in the two-party margin per standard deviation of the measure (positive is toward the Democrats)Estimandweighted least squares coefficient of the share of returns claiming the earned income tax credit, net of the poverty rate, college share, Black share and Hispanic share (95% interval clustered on state, 49 clusters)Interval95% CI −1.2 to 1.9n27,144Weightsvotes cast in the ZIP code in 2020 (pres_tot_2020)PopulationZIP code tabulation areas in the contiguous states with more than 100 votes in 2020 and complete IRS and ACS measuresPeriod2016 to 2020 swing; IRS tax year 2022; ACS 5-year estimatesSourcePrecinct votes on census geographies with clusters on state). A ZIP code with many EITC claims is, on average, poor, has a lower college share and has more Black and Hispanic residents: the EITC share correlates −0.72 (95% CI −0.74 to −0.71)−0.72 correlation coefficient, from −1 to +1Estimandcorrelation of the EITC share with the college share (vote-weighted; 95% interval from a bootstrap of counties, 2,000 replicates)Interval95% CI −0.74 to −0.71n27,144Weightsvotes cast in the ZIP code in 2020 (pres_tot_2020)PopulationZIP code tabulation areas in the contiguous states with more than 100 votes in 2020 and complete IRS and ACS measuresPeriod2016 to 2020 swing; IRS tax year 2022; ACS 5-year estimatesSourcePrecinct votes on census geographies with the college share (−0.56−0.56 correlation coefficient, from −1 to +1Estimandcorrelation of the EITC share with the college share, every ZIP code counted equally (95% interval from a bootstrap of counties, 2,000 replicates)Interval95% CI −0.58 to −0.54n27,144Weightsnone (every ZIP code counted equally)PopulationZIP code tabulation areas in the contiguous states with more than 100 votes in 2020 and complete IRS and ACS measuresPeriod2016 to 2020 swing; IRS tax year 2022; ACS 5-year estimatesSourcePrecinct votes on census geographies with each ZIP code counted equally). The link between the EITC share and the swing is therefore partly a link between those characteristics and the swing, and the data do not show a separate association once they are held fixed. Chapter 13.3, Deprivation and mobility (planned) asks the same question of neighborhood deprivation, with race held fixed.
Starr County, Texas, and Holmes County, Mississippi, illustrate that the EITC share alone does not fix the swing. They have nearly the same share of returns claiming the credit, 45.4%45.4% percent of returnsEstimandvote-weighted mean of the ZIP-code EITC share in the countyWeightsvotes cast in the ZIP code in 2020 (pres_tot_2020)Populationreturns in Starr County, TexasPeriodIRS tax year 2022SourceIRS SOI ZIP code data and 45.2%45.2% percent of returnsEstimandvote-weighted mean of the ZIP-code EITC share in the countyWeightsvotes cast in the ZIP code in 2020 (pres_tot_2020)Populationreturns in Holmes County, MississippiPeriodIRS tax year 2022SourceIRS SOI ZIP code data. Between 2016 and 2020 Starr swung 56.356.3 points of two-party margin swing, toward the RepublicansEstimandcounty two-party margin in 2020 minus 2016, sign reversed to a size toward the RepublicansWeightsnone (full count of votes)Populationtwo-party voters in Starr County, TexasPeriod2016 to 2020SourceCounty election returns points toward the Republicans, the largest such swing of any county in the county sample, and Holmes 1.71.7 points of two-party margin swing, toward the RepublicansEstimandcounty two-party margin in 2020 minus 2016, sign reversed to a size toward the RepublicansWeightsnone (full count of votes)Populationtwo-party voters in Holmes County, MississippiPeriod2016 to 2020SourceCounty election returns points toward the Republicans. The Hispanic share of residents is 98.1%98.1% percent of residentsEstimandHispanic share of residentsWeightsnone (full counts and interpolated estimates)Populationresidents of Starr County, TexasPeriodcounty demographics centred on 2020SourceCounty demographics panel in Starr and the Black share is 82.4%82.4% percent of residentsEstimandBlack share of residentsWeightsnone (full counts and interpolated estimates)Populationresidents of Holmes County, MississippiPeriodcounty demographics centred on 2020SourceCounty demographics panel in Holmes, and both shares are in the full set of controls. The pair is picked for the contrast, and the ZIP-code regressions do not test whether these shares account for either swing.
The average tax rate was included as a rough stand-in for income, and it is a poor control. It correlates +0.90 (95% CI 0.89 to 0.91)+0.90 correlation coefficient, from −1 to +1Estimandcorrelation of the capital-gains share with the average tax rate (vote-weighted; 95% interval from a bootstrap of counties, 2,000 replicates)Interval95% CI 0.89 to 0.91n27,144Weightsvotes cast in the ZIP code in 2020 (pres_tot_2020)PopulationZIP code tabulation areas in the contiguous states with more than 100 votes in 2020 and complete IRS and ACS measuresPeriod2016 to 2020 swing; IRS tax year 2022; ACS 5-year estimatesSourcePrecinct votes on census geographies with the capital-gains share and −0.67 (95% CI −0.69 to −0.65)−0.67 correlation coefficient, from −1 to +1Estimandcorrelation of the EITC share with the average tax rate (vote-weighted; 95% interval from a bootstrap of counties, 2,000 replicates)Interval95% CI −0.69 to −0.65n27,144Weightsvotes cast in the ZIP code in 2020 (pres_tot_2020)PopulationZIP code tabulation areas in the contiguous states with more than 100 votes in 2020 and complete IRS and ACS measuresPeriod2016 to 2020 swing; IRS tax year 2022; ACS 5-year estimatesSourcePrecinct votes on census geographies with the EITC share, so it is highest in the ZIP codes with many capital-gains returns and lowest where EITC claims are common, and holding it fixed leaves 19%19% percent of the variance of the capital-gains shareEstimandone minus the squared vote-weighted correlation of the capital-gains share with the average tax rateWeightsvotes cast in the ZIP code in 2020 (pres_tot_2020)PopulationZIP code tabulation areas in the contiguous states with more than 100 votes in 2020 and complete IRS and ACS measuresPeriod2016 to 2020 swing; IRS tax year 2022; ACS 5-year estimatesSourcePrecinct votes on census geographies of the variance of the capital-gains share. It may itself respond to either share, since the credit reduces the tax a filer owes and gains are taxed under their own rates. The rows that hold it fixed rest on a near-collinear control and are the least reliable in the ladder.
Counties show the same raw signs, with wide intervals
Figure 5 maps both shares and the swing by county. Each county averages the shares of its ZIP codes with weights of 2020 votes and takes the swing from certified county returns. The county correlation of the EITC share with the swing is −0.42 (95% CI −0.58 to −0.23)−0.42 correlation coefficient, from −1 to +1Estimandcorrelation of the county EITC share with the 2016 to 2020 swing (95% interval from a bootstrap of states)Interval95% CI −0.58 to −0.23n3,080Weightstwo-party votes cast in the county in 2020Populationcounties in the contiguous states with ZIP-code shares and county demographicsPeriod2016 to 2020 swing; IRS tax year 2022; county demographics centred on 2020SourceCounty election returns (−0.44−0.44 correlation coefficient, from −1 to +1Estimandcorrelation of the county EITC share with the 2016 to 2020 swing, every county counted equally (95% interval from a bootstrap of states)Interval95% CI −0.54 to −0.33n3,080Weightsnone (every county counted equally)Populationcounties in the contiguous states with ZIP-code shares and county demographicsPeriod2016 to 2020 swing; IRS tax year 2022; county demographics centred on 2020SourceCounty election returns with each county counted equally) and of the capital-gains share +0.21 (95% CI 0.04 to 0.40)+0.21 correlation coefficient, from −1 to +1Estimandcorrelation of the county capital-gains share with the 2016 to 2020 swing (95% interval from a bootstrap of states)Interval95% CI 0.04 to 0.40n3,080Weightstwo-party votes cast in the county in 2020Populationcounties in the contiguous states with ZIP-code shares and county demographicsPeriod2016 to 2020 swing; IRS tax year 2022; county demographics centred on 2020SourceCounty election returns (+0.41+0.41 correlation coefficient, from −1 to +1Estimandcorrelation of the county capital-gains share with the 2016 to 2020 swing, every county counted equally (95% interval from a bootstrap of states)Interval95% CI 0.33 to 0.49n3,080Weightsnone (every county counted equally)Populationcounties in the contiguous states with ZIP-code shares and county demographicsPeriod2016 to 2020 swing; IRS tax year 2022; county demographics centred on 2020SourceCounty election returns), the same signs as in the ZIP codes. This changes the geographic grain and the source of the vote and is not an independent test of the IRS shares, which are the same ZIP-code values averaged. Intervals cluster on state, with 4848 states and the District of ColumbiaEstimandcount of state clusters in the county modelsWeightsnone (count)Populationstates and the District of Columbia with a county in the county samplePeriod2016 and 2020SourceCounty election returns clusters (the states and the District of Columbia, without Connecticut), and are wider.
Figure 5
The EITC share is highest in the Mississippi Delta, Alabama's Black Belt and along the Rio Grande
Share of returns claiming the earned income tax credit by county, IRS tax year 2022, averaged from ZIP codes within the county
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Share of returns claiming the earned income tax credit (%)
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Figure 6 repeats the ZIP-code ladder at county grain with the county bachelor's share as the college control; its second view adds the row that holds only the average tax rate fixed. The capital-gains share correlates +0.83 (95% CI 0.77 to 0.87)+0.83 correlation coefficient, from −1 to +1Estimandcorrelation of the county capital-gains share with the county bachelor's share (95% interval from a bootstrap of states)Interval95% CI 0.77 to 0.87n3,080Weightstwo-party votes cast in the county in 2020Populationcounties in the contiguous states with ZIP-code shares and county demographicsPeriod2016 to 2020 swing; IRS tax year 2022; county demographics centred on 2020SourceCounty election returns with the bachelor's share across counties (+0.68+0.68 correlation coefficient, from −1 to +1Estimandcorrelation of the county capital-gains share with the county bachelor's share, every county counted equally (95% interval from a bootstrap of states)Interval95% CI 0.60 to 0.76n3,080Weightsnone (every county counted equally)Populationcounties in the contiguous states with ZIP-code shares and county demographicsPeriod2016 to 2020 swing; IRS tax year 2022; county demographics centred on 2020SourceCounty election returns with each county counted equally). The capital-gains coefficient is +1.2 (95% CI 0.0 to 2.4)+1.2 points of swing in the two-party margin per standard deviation of the measure (positive is toward the Democrats)Estimandweighted least squares coefficient of the share of returns reporting a net capital gain, with no controls (95% interval clustered on state)Interval95% CI 0.0 to 2.4n3,080Weightstwo-party votes cast in the county in 2020Populationcounties in the contiguous states with ZIP-code shares and county demographicsPeriod2016 to 2020 swing; IRS tax year 2022; county demographics centred on 2020SourceCounty election returns with no controls, +0.1 (95% CI −1.7 to 2.0)+0.1 points of swing in the two-party margin per standard deviation of the measure (positive is toward the Democrats)Estimandweighted least squares coefficient of the share of returns reporting a net capital gain, net of the college share (95% interval clustered on state)Interval95% CI −1.7 to 2.0n3,080Weightstwo-party votes cast in the county in 2020Populationcounties in the contiguous states with ZIP-code shares and county demographicsPeriod2016 to 2020 swing; IRS tax year 2022; county demographics centred on 2020SourceCounty election returns with the bachelor's share held fixed and −2.9 (95% CI −4.4 to −1.5)−2.9 points of swing in the two-party margin per standard deviation of the measure (positive is toward the Democrats)Estimandweighted least squares coefficient of the share of returns reporting a net capital gain, net of the poverty rate, college share, Black share and Hispanic share (95% interval clustered on state)Interval95% CI −4.4 to −1.5n3,080Weightstwo-party votes cast in the county in 2020Populationcounties in the contiguous states with ZIP-code shares and county demographicsPeriod2016 to 2020 swing; IRS tax year 2022; county demographics centred on 2020SourceCounty election returns with the full set held fixed, and the first two intervals include zero. With the average tax rate and the bachelor's share held fixed together it is +2.7 (95% CI 0.4 to 4.9)+2.7 points of swing in the two-party margin per standard deviation of the measure (positive is toward the Democrats)Estimandweighted least squares coefficient of the share of returns reporting a net capital gain, net of the average tax rate and the college share (95% interval clustered on state)Interval95% CI 0.4 to 4.9n3,080Weightstwo-party votes cast in the county in 2020Populationcounties in the contiguous states with ZIP-code shares and county demographicsPeriod2016 to 2020 swing; IRS tax year 2022; county demographics centred on 2020SourceCounty election returns, an interval above zero. The EITC coefficient is −2.4 (95% CI −3.6 to −1.1)−2.4 points of swing in the two-party margin per standard deviation of the measure (positive is toward the Democrats)Estimandweighted least squares coefficient of the share of returns claiming the earned income tax credit, with no controls (95% interval clustered on state)Interval95% CI −3.6 to −1.1n3,080Weightstwo-party votes cast in the county in 2020Populationcounties in the contiguous states with ZIP-code shares and county demographicsPeriod2016 to 2020 swing; IRS tax year 2022; county demographics centred on 2020SourceCounty election returns with no controls, −2.5 (95% CI −4.2 to −0.8)−2.5 points of swing in the two-party margin per standard deviation of the measure (positive is toward the Democrats)Estimandweighted least squares coefficient of the share of returns claiming the earned income tax credit, net of the college share (95% interval clustered on state)Interval95% CI −4.2 to −0.8n3,080Weightstwo-party votes cast in the county in 2020Populationcounties in the contiguous states with ZIP-code shares and county demographicsPeriod2016 to 2020 swing; IRS tax year 2022; county demographics centred on 2020SourceCounty election returns with the bachelor's share held fixed and 0.0 (95% CI −2.4 to 2.4)0.0 points of swing in the two-party margin per standard deviation of the measure (positive is toward the Democrats)Estimandweighted least squares coefficient of the share of returns claiming the earned income tax credit, net of the poverty rate, college share, Black share and Hispanic share (95% interval clustered on state)Interval95% CI −2.4 to 2.4n3,080Weightstwo-party votes cast in the county in 2020Populationcounties in the contiguous states with ZIP-code shares and county demographicsPeriod2016 to 2020 swing; IRS tax year 2022; county demographics centred on 2020SourceCounty election returns with the poverty rate, bachelor's share, Black share and Hispanic share held fixed, an interval that includes zero. The county intervals are wide. The interval for the capital-gains coefficient with the bachelor's share held fixed includes both zero and the ZIP-code estimate with the college share held fixed (−1.0 (95% CI −2.1 to 0.0)−1.0 points of swing in the two-party margin per standard deviation of the measure (positive is toward the Democrats)Estimandweighted least squares coefficient of the share of returns reporting a net capital gain, net of the college share (95% interval clustered on state, 49 clusters)Interval95% CI −2.1 to 0.0n27,144Weightsvotes cast in the ZIP code in 2020 (pres_tot_2020)PopulationZIP code tabulation areas in the contiguous states with more than 100 votes in 2020 and complete IRS and ACS measuresPeriod2016 to 2020 swing; IRS tax year 2022; ACS 5-year estimatesSourcePrecinct votes on census geographies with clusters on state), so the county data cannot say whether the capital-gains coefficient after education is near zero or negative, and they do not show that the ZIP-code and county results differ. Under the full set the coefficient is negative at both grains. Chapter 12.3, Income and the county vote (planned) takes county income directly.
Figure 6
At county grain the intervals are wide and the capital-gains coefficient with college held fixed includes zero
Weighted regression coefficient of the 2016 to 2020 county swing on the county share of returns, one set of controls per row; 95% intervals clustered on state
EITC share
Capital-gains share
Points of swing per standard deviation of the share (positive is toward the Democrats)
Show data
| Share | Controls | Coefficient | Lower bound | Upper bound | Interval | Counties | State clusters |
|---|---|---|---|---|---|---|---|
| EITC share | No controls | −2.39 | −3.65 | −1.14 | Below zero | 3,080 | 48 |
| EITC share | Poverty rate | −0.90 | −3.56 | +1.76 | Includes zero | 3,080 | 48 |
| EITC share | Average tax rate | −3.44 | −5.03 | −1.84 | Below zero | 3,080 | 48 |
| EITC share | College share | −2.53 | −4.20 | −0.85 | Below zero | 3,080 | 48 |
| EITC share | Average tax rate and college share | −3.00 | −4.52 | −1.49 | Below zero | 3,080 | 48 |
| EITC share | Poverty, college, Black and Hispanic shares | +0.01 | −2.40 | +2.43 | Includes zero | 3,080 | 48 |
| Capital-gains share | No controls | +1.18 | −0.01 | +2.37 | Includes zero | 3,080 | 48 |
| Capital-gains share | Poverty rate | −0.82 | −2.01 | +0.38 | Includes zero | 3,080 | 48 |
| Capital-gains share | Average tax rate | +3.67 | +1.54 | +5.81 | Above zero | 3,080 | 48 |
| Capital-gains share | College share | +0.14 | −1.72 | +1.99 | Includes zero | 3,080 | 48 |
| Capital-gains share | Average tax rate and college share | +2.67 | +0.40 | +4.94 | Above zero | 3,080 | 48 |
| Capital-gains share | Poverty, college, Black and Hispanic shares | −2.93 | −4.40 | −1.46 | Below zero | 3,080 | 48 |
Investors and homeowners lean Republican within education groups
The ZIP-code results describe places. The Cooperative Election Study asks respondents whether they have money invested in the stock market and whether they own their home, and it records their vote, so it can compare people with the same education. A college degree here means a four-year degree or more. Figure 7 gives the Democratic minus Republican margin among voters for the two major parties in 2020 and in 2016. The investor comparison rests on 43,78543,785 respondentsEstimandcount of two-party voters with a degree, a weight and an answer to the investor item (owning or renting for the homeowner item)Weightsnone (count)PopulationCES respondents who reported voting for the Democratic or the Republican presidential candidatePeriod2020SourceCooperative Election Study voters in 2020 and 40,80340,803 respondentsEstimandcount of two-party voters with a degree, a weight and an answer to the investor item (owning or renting for the homeowner item)Weightsnone (count)PopulationCES respondents who reported voting for the Democratic or the Republican presidential candidatePeriod2016SourceCooperative Election Study in 2016 and the homeowner comparison on 42,14242,142 respondentsEstimandcount of two-party voters with a degree, a weight and an answer to the homeowner item (owning or renting for the homeowner item)Weightsnone (count)PopulationCES respondents who reported voting for the Democratic or the Republican presidential candidatePeriod2020SourceCooperative Election Study and 39,45839,458 respondentsEstimandcount of two-party voters with a degree, a weight and an answer to the homeowner item (owning or renting for the homeowner item)Weightsnone (count)PopulationCES respondents who reported voting for the Democratic or the Republican presidential candidatePeriod2016SourceCooperative Election Study, after setting aside voters without an answer to the item and, for homeowners, voters who report a housing status other than owning or renting.
Among voters without a college degree, investors were 27.1 (95% CI 23.4 to 30.8)27.1 points of two-party margin, how much more Republican the first group isEstimanddifference in the Democratic minus Republican margin between investors and non-investors, shown as a size (Kish effective-sample interval)Interval95% CI 23.4 to 30.8Weightspost-election weight (weight_post)PopulationCES respondents who reported voting for the Democratic or the Republican presidential candidate; no college degreePeriod2020SourceCooperative Election Study points more Republican than non-investors in 2020 and 18.1 (95% CI 14.2 to 21.9)18.1 points of two-party margin, how much more Republican the first group isEstimanddifference in the Democratic minus Republican margin between investors and non-investors, shown as a size (Kish effective-sample interval)Interval95% CI 14.2 to 21.9Weightspost-election weight (weight_post)PopulationCES respondents who reported voting for the Democratic or the Republican presidential candidate; no college degreePeriod2016SourceCooperative Election Study points more Republican in 2016. Among college graduates the gaps were 10.3 (95% CI 6.5 to 14.2)10.3 points of two-party margin, how much more Republican the first group isEstimanddifference in the Democratic minus Republican margin between investors and non-investors, shown as a size (Kish effective-sample interval)Interval95% CI 6.5 to 14.2Weightspost-election weight (weight_post)PopulationCES respondents who reported voting for the Democratic or the Republican presidential candidate; college degreePeriod2020SourceCooperative Election Study and 5.9 (95% CI 2.2 to 9.6)5.9 points of two-party margin, how much more Republican the first group isEstimanddifference in the Democratic minus Republican margin between investors and non-investors, shown as a size (Kish effective-sample interval)Interval95% CI 2.2 to 9.6Weightspost-election weight (weight_post)PopulationCES respondents who reported voting for the Democratic or the Republican presidential candidate; college degreePeriod2016SourceCooperative Election Study points. Homeowners were more Republican than renters at both education levels: 46.7 (95% CI 42.5 to 50.9)46.7 points of two-party margin, how much more Republican the first group isEstimanddifference in the Democratic minus Republican margin between homeowners and renters, shown as a size (Kish effective-sample interval)Interval95% CI 42.5 to 50.9Weightspost-election weight (weight_post)PopulationCES respondents who reported voting for the Democratic or the Republican presidential candidate; no college degreePeriod2020SourceCooperative Election Study points among non-graduates and 38.0 (95% CI 34.1 to 41.9)38.0 points of two-party margin, how much more Republican the first group isEstimanddifference in the Democratic minus Republican margin between homeowners and renters, shown as a size (Kish effective-sample interval)Interval95% CI 34.1 to 41.9Weightspost-election weight (weight_post)PopulationCES respondents who reported voting for the Democratic or the Republican presidential candidate; college degreePeriod2020SourceCooperative Election Study points among graduates in 2020, and 47.4 (95% CI 43.3 to 51.6)47.4 points of two-party margin, how much more Republican the first group isEstimanddifference in the Democratic minus Republican margin between homeowners and renters, shown as a size (Kish effective-sample interval)Interval95% CI 43.3 to 51.6Weightspost-election weight (weight_post)PopulationCES respondents who reported voting for the Democratic or the Republican presidential candidate; no college degreePeriod2016SourceCooperative Election Study and 37.1 (95% CI 33.0 to 41.1)37.1 points of two-party margin, how much more Republican the first group isEstimanddifference in the Democratic minus Republican margin between homeowners and renters, shown as a size (Kish effective-sample interval)Interval95% CI 33.0 to 41.1Weightspost-election weight (weight_post)PopulationCES respondents who reported voting for the Democratic or the Republican presidential candidate; college degreePeriod2016SourceCooperative Election Study points in 2016.
Figure 7
Investors voted more Republican than non-investors with the same education in 2016 and 2020
Democratic minus Republican margin among voters for the two major parties, by year, education and whether the respondent reports investments; 95% intervals; positive is toward the Democrats
- Non-investors
- Investors
Show data
| Item | Year and education | Group | Margin (points) | Lower bound | Upper bound | Voters | Comparison group | Margin (points) | Lower bound | Upper bound | Voters | Group minus comparison (points) | Lower bound | Upper bound | Group's change, 2016 to 2020 (points) | Lower bound | Upper bound | Comparison group's change (points) | Lower bound | Upper bound | Group's change minus comparison's (points) | Lower bound | Upper bound |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| investor | 2016, no college degree | Investors | −15.2 | −18.2 | −12.2 | 9,191 | Non-investors | +2.9 | +0.4 | +5.3 | 15,098 | −18.1 | −21.9 | −14.2 | n/a | n/a | n/a | n/a | n/a | n/a | n/a | n/a | n/a |
| investor | 2020, no college degree | Investors | −20.7 | −23.5 | −18.0 | 9,501 | Non-investors | +6.4 | +3.8 | +8.9 | 15,452 | −27.1 | −30.8 | −23.4 | −5.5 | −9.6 | −1.5 | +3.5 | 0.0 | +7.0 | −9.1 | −14.4 | −3.7 |
| investor | 2016, college degree | Investors | +14.9 | +12.6 | +17.1 | 10,328 | Non-investors | +20.8 | +17.8 | +23.8 | 6,186 | −5.9 | −9.6 | −2.2 | n/a | n/a | n/a | n/a | n/a | n/a | n/a | n/a | n/a |
| investor | 2020, college degree | Investors | +19.4 | +17.3 | +21.4 | 12,826 | Non-investors | +29.7 | +26.4 | +32.9 | 6,006 | −10.3 | −14.2 | −6.5 | +4.5 | +1.4 | +7.5 | +8.9 | +4.5 | +13.3 | −4.4 | −9.7 | +1.0 |
| homeowner | 2016, no college degree | Homeowners | −20.1 | −22.3 | −17.9 | 16,702 | Renters | +27.3 | +23.8 | +30.8 | 6,697 | −47.4 | −51.6 | −43.3 | n/a | n/a | n/a | n/a | n/a | n/a | n/a | n/a | n/a |
| homeowner | 2020, no college degree | Homeowners | −20.6 | −22.8 | −18.4 | 16,241 | Renters | +26.2 | +22.6 | +29.7 | 7,650 | −46.7 | −50.9 | −42.5 | −0.4 | −3.5 | +2.7 | −1.1 | −6.2 | +3.9 | +0.7 | −5.2 | +6.6 |
| homeowner | 2016, college degree | Homeowners | +7.9 | +5.8 | +9.9 | 12,186 | Renters | +44.9 | +41.5 | +48.4 | 3,873 | −37.1 | −41.1 | −33.0 | n/a | n/a | n/a | n/a | n/a | n/a | n/a | n/a | n/a |
| homeowner | 2020, college degree | Homeowners | +12.7 | +10.6 | +14.7 | 13,685 | Renters | +50.6 | +47.3 | +54.0 | 4,566 | −38.0 | −41.9 | −34.1 | +4.8 | +1.9 | +7.7 | +5.7 | +0.9 | +10.5 | −0.9 | −6.5 | +4.7 |
The survey also allows a comparison with the swing, with a caution: the 2016 and 2020 samples are separate cross-sections, and the groups change. The investor share of graduate voters is 63.7% (95% CI 62.8% to 64.6%)63.7% percent of votersEstimandweighted share who report investmentsInterval95% CI 62.8% to 64.6%n16,514Weightspost-election weight (weight_post)PopulationCES respondents who reported voting for the Democratic or the Republican presidential candidate; college degreePeriod2016SourceCooperative Election Study in 2016 and 67.9% (95% CI 67.0% to 68.7%)67.9% percent of votersEstimandweighted share who report investmentsInterval95% CI 67.0% to 68.7%n18,832Weightspost-election weight (weight_post)PopulationCES respondents who reported voting for the Democratic or the Republican presidential candidate; college degreePeriod2020SourceCooperative Election Study in 2020, and of other voters 33.8%33.8% percent of votersEstimandweighted share who report investmentsInterval95% CI 32.9% to 34.7%n24,289Weightspost-election weight (weight_post)PopulationCES respondents who reported voting for the Democratic or the Republican presidential candidate; no college degreePeriod2016SourceCooperative Election Study and 35.1%35.1% percent of votersEstimandweighted share who report investmentsInterval95% CI 34.2% to 36.0%n24,953Weightspost-election weight (weight_post)PopulationCES respondents who reported voting for the Democratic or the Republican presidential candidate; no college degreePeriod2020SourceCooperative Election Study. Between 2016 and 2020 the margin of investors without a degree moved 5.5 (95% CI 1.5 to 9.6)5.5 points of two-party margin, how far the group moved toward the RepublicansEstimandchange in the margin from 2016 to 2020 for investors, shown as a size in the direction of the move (Kish effective-sample interval)Interval95% CI 1.5 to 9.6Weightspost-election weight (weight_post)PopulationCES respondents who reported voting for the Democratic or the Republican presidential candidate; no college degree; investorsPeriod2016 to 2020SourceCooperative Election Study points toward the Republicans, and the margin of non-investors without a degree moved 3.5 (95% CI 0.0 to 7.0)3.5 points of two-party margin, how far the group moved toward the DemocratsEstimandchange in the margin from 2016 to 2020 for non-investors, shown as a size in the direction of the move (Kish effective-sample interval)Interval95% CI 0.0 to 7.0Weightspost-election weight (weight_post)PopulationCES respondents who reported voting for the Democratic or the Republican presidential candidate; no college degree; non-investorsPeriod2016 to 2020SourceCooperative Election Study points toward the Democrats (the interval starts at zero), a difference of 9.1 (95% CI 3.7 to 14.4)9.1 points of two-party margin, how much less the first group moved toward the DemocratsEstimandchange in the margin from 2016 to 2020 for investors and non-investors, first group minus second, sign reversed to a size (Kish effective-sample interval)Interval95% CI 3.7 to 14.4Weightspost-election weight (weight_post)PopulationCES respondents who reported voting for the Democratic or the Republican presidential candidate; no college degreePeriod2016 to 2020SourceCooperative Election Study points. Among graduates, investors moved 4.5 (95% CI 1.4 to 7.5)4.5 points of two-party margin, how far the group moved toward the DemocratsEstimandchange in the margin from 2016 to 2020 for investors, shown as a size in the direction of the move (Kish effective-sample interval)Interval95% CI 1.4 to 7.5Weightspost-election weight (weight_post)PopulationCES respondents who reported voting for the Democratic or the Republican presidential candidate; college degree; investorsPeriod2016 to 2020SourceCooperative Election Study points toward the Democrats and non-investors 8.9 (95% CI 4.5 to 13.3)8.9 points of two-party margin, how far the group moved toward the DemocratsEstimandchange in the margin from 2016 to 2020 for non-investors, shown as a size in the direction of the move (Kish effective-sample interval)Interval95% CI 4.5 to 13.3Weightspost-election weight (weight_post)PopulationCES respondents who reported voting for the Democratic or the Republican presidential candidate; college degree; non-investorsPeriod2016 to 2020SourceCooperative Election Study, a difference of 4.4 (95% CI −1.0 to 9.7)4.4 points of two-party margin, how much less the first group moved toward the DemocratsEstimandchange in the margin from 2016 to 2020 for investors and non-investors, first group minus second, sign reversed to a size (Kish effective-sample interval)Interval95% CI −1.0 to 9.7Weightspost-election weight (weight_post)PopulationCES respondents who reported voting for the Democratic or the Republican presidential candidate; college degreePeriod2016 to 2020SourceCooperative Election Study points, an interval that includes zero. The differences are computed from unrounded moves. Investors without a degree therefore moved toward the Republicans while non-investors without a degree moved toward the Democrats, and the data do not show a difference among graduates. Homeowners without a degree moved 0.7 (95% CI −5.2 to 6.6)0.7 points of two-party margin, how much more the first group moved toward the Democrats than the secondEstimandchange in the margin from 2016 to 2020 for homeowners and renters, first group minus second, shown as a size above the second group (Kish effective-sample interval)Interval95% CI −5.2 to 6.6Weightspost-election weight (weight_post)PopulationCES respondents who reported voting for the Democratic or the Republican presidential candidate; no college degreePeriod2016 to 2020SourceCooperative Election Study points more toward the Democrats than renters without a degree, and homeowners with a degree moved 0.9 (95% CI −4.7 to 6.5)0.9 points of two-party margin, how much less the first group moved toward the Democrats than the secondEstimandchange in the margin from 2016 to 2020 for homeowners and renters, first group minus second, shown as a size below the second group (Kish effective-sample interval)Interval95% CI −4.7 to 6.5Weightspost-election weight (weight_post)PopulationCES respondents who reported voting for the Democratic or the Republican presidential candidate; college degreePeriod2016 to 2020SourceCooperative Election Study points less than renters with a degree. Both homeowner intervals include zero and are wide, so the data do not show whether homeowners and renters moved alike.
The individual pattern is consistent with the same composition as the ZIP-code pattern. College graduates are more likely to invest, 67.9% (95% CI 67.0% to 68.7%)67.9% percent of votersEstimandweighted share who report investmentsInterval95% CI 67.0% to 68.7%n18,832Weightspost-election weight (weight_post)PopulationCES respondents who reported voting for the Democratic or the Republican presidential candidate; college degreePeriod2020SourceCooperative Election Study of graduate voters in 2020 against 35.1% (95% CI 34.2% to 36.0%)35.1% percent of votersEstimandweighted share who report investmentsInterval95% CI 34.2% to 36.0%n24,953Weightspost-election weight (weight_post)PopulationCES respondents who reported voting for the Democratic or the Republican presidential candidate; no college degreePeriod2020SourceCooperative Election Study of others, and graduates vote more Democratic than non-graduates within every investor and housing group in the figure. A ZIP code with many college-educated adults has many capital-gains returns and moved toward the Democrats, while an investor with a given degree leans Republican relative to a non-investor with the same degree. The ZIP-code college variable has an unresolved definition and the survey measure is a four-year degree, so the two may not be the same split. Gelman and coauthors found a similar reversal between states and individuals: richer states vote more Democratic while richer individuals within them vote more Republican [5]. Chapter 3.3, The income ladder follows the individual vote by family income.
What these data cannot show
The ZIP-code results are associations between places and do not say how a capital-gains filer or an EITC claimant voted. Group and individual correlations can differ [6], and this chapter has one case. The raw ZIP-code coefficient of the swing on the capital-gains share is +2.4+2.4 points of swing in the two-party margin per standard deviation of the measure (positive is toward the Democrats)Estimandweighted least squares coefficient of the share of returns reporting a net capital gain, with no controls (95% interval clustered on county)Interval95% CI 2.0 to 2.9n27,144Weightsvotes cast in the ZIP code in 2020 (pres_tot_2020)PopulationZIP code tabulation areas in the contiguous states with more than 100 votes in 2020 and complete IRS and ACS measuresPeriod2016 to 2020 swing; IRS tax year 2022; ACS 5-year estimatesSourcePrecinct votes on census geographies, while among voters without a degree investors moved 5.55.5 points of two-party margin, how far the group moved toward the RepublicansEstimandchange in the margin from 2016 to 2020 for investors, shown as a size in the direction of the move (Kish effective-sample interval)Interval95% CI 1.5 to 9.6Weightspost-election weight (weight_post)PopulationCES respondents who reported voting for the Democratic or the Republican presidential candidate; no college degree; investorsPeriod2016 to 2020SourceCooperative Election Study points toward the Republicans and non-investors 3.53.5 points of two-party margin, how far the group moved toward the DemocratsEstimandchange in the margin from 2016 to 2020 for non-investors, shown as a size in the direction of the move (Kish effective-sample interval)Interval95% CI 0.0 to 7.0Weightspost-election weight (weight_post)PopulationCES respondents who reported voting for the Democratic or the Republican presidential candidate; no college degree; non-investorsPeriod2016 to 2020SourceCooperative Election Study points toward the Democrats. With the college share held fixed the ZIP-code coefficient is −1.0−1.0 points of swing in the two-party margin per standard deviation of the measure (positive is toward the Democrats)Estimandweighted least squares coefficient of the share of returns reporting a net capital gain, net of the college share (95% interval clustered on county)Interval95% CI −1.6 to −0.4n27,144Weightsvotes cast in the ZIP code in 2020 (pres_tot_2020)PopulationZIP code tabulation areas in the contiguous states with more than 100 votes in 2020 and complete IRS and ACS measuresPeriod2016 to 2020 swing; IRS tax year 2022; ACS 5-year estimatesSourcePrecinct votes on census geographies, the same sign as the survey difference, though its interval includes zero when clustered on state. The place-level and voter-level results disagree about the raw association and agree in sign once education is held fixed, which is what the composition account above predicts. This is ecological inferenceEcological inferenceDrawing a conclusion about individuals from data on groups or places, such as counties. A pattern across counties can differ from the pattern among the people who live in them., and the ZIP-code filers and voters are overlapping but not identical populations.
The timing is a limit. The IRS shares are for tax year 2022 and the swing is for 2016 to 2020, so a ZIP code's income mix is measured after both elections. The release of the American Community Survey behind the ZIP-code controls is not recorded in the demographic file, so the controls cannot be dated against the swing. The IRS shares describe filers, so the poorest households and some retirees are missing, and the EITC share is a share of returns and not of residents. The vote estimates are allocations of precinct returns to ZIP codes, with a source change between 2016 and 2020, and both the allocation error and the source change enter the swing. The IRS file also omits PO-box ZIP codes and ZIP codes below its disclosure thresholds, so some ZIP codes with votes have no share; Figure 8 counts what each step of the sample leaves out.
Figure 8
The ZIP-code sample is 27,144 areas in 3,088 counties and the county sample is 3,080 counties
Counts of ZIP code tabulation areas and counties at each step from the vote file to the two analysis samples
| Sample | ZIP code tabulation areas | Counties containing these areas |
|---|---|---|
| ZIP code tabulation areas with vote estimates for 2016 and 2020 | 32,428 | 3,102 |
| With more than 100 votes in 2020 | 29,420 | 3,100 |
| With both IRS shares and a swing | 27,170 | 3,089 |
| With the average tax rate and four ACS controls: the ZIP-code sample | 27,144 | 3,088 |
| Counties with a two-party return in 2016 and 2020 | n/a | 3,113 |
| With ZIP-code shares | n/a | 3,088 |
| With county demographics: the county sample | n/a | 3,080 |
Show data
| counties | step | zcta |
|---|---|---|
| 3,102 | ZIP code tabulation areas with vote estimates for 2016 and 2020 | 32428 |
| 3,100 | With more than 100 votes in 2020 | 29420 |
| 3,089 | With both IRS shares and a swing | 27170 |
| 3,088 | With the average tax rate and four ACS controls: the ZIP-code sample | 27144 |
| 3,113 | Counties with a two-party return in 2016 and 2020 | n/a |
| 3,088 | With ZIP-code shares | n/a |
| 3,080 | With county demographics: the county sample | n/a |
The intervals allow dependence among ZIP codes in the same county (or, in the state check, the same state) and not between neighboring counties in different states or between neighboring states. Regional swings, such as the swing in the Texas border counties, make that dependence likely, and the two capital-gains intervals that change between the county and state clusterings show that it can matter for a conclusion. The shares of the smallest ZIP codes rest on few returns. In the sample, 1,4051,405 ZIP code tabulation areasEstimandcount of ZCTAs with exactly 0% of returns reporting a net capital gainWeightsnone (count)PopulationZIP code tabulation areas in the contiguous states with more than 100 votes in 2020 and complete IRS and ACS measuresPeriodIRS tax year 2022SourceIRS SOI ZIP code data ZIP codes report no capital-gains returns and 1,2441,244 ZIP code tabulation areasEstimandcount of ZCTAs with exactly 0% of returns claiming the EITCWeightsnone (count)PopulationZIP code tabulation areas in the contiguous states with more than 100 votes in 2020 and complete IRS and ACS measuresPeriodIRS tax year 2022SourceIRS SOI ZIP code data report no EITC returns, and the data do not distinguish a true zero from a small count rounded down. They hold 0.3%0.3% percent of votesEstimandshare of the sample's 2020 votes in ZCTAs with exactly 0% capital-gains returnsWeightsnone (count)PopulationZIP code tabulation areas in the contiguous states with more than 100 votes in 2020 and complete IRS and ACS measuresPeriod2020SourcePrecinct votes on census geographies and 0.2%0.2% percent of votesEstimandshare of the sample's 2020 votes in ZCTAs with exactly 0% EITC returnsWeightsnone (count)PopulationZIP code tabulation areas in the contiguous states with more than 100 votes in 2020 and complete IRS and ACS measuresPeriod2020SourcePrecinct votes on census geographies of the votes in the sample, and leaving them out of the lowest decile moves its mean swing from 7.27.2 points of two-party margin swing, toward the RepublicansEstimandvote-weighted mean swing of the decile, shown as a size (95% interval clustered on county)Interval95% CI 5.6 to 8.8n2,715Weightsvotes cast in the ZIP code in 2020 (pres_tot_2020)PopulationZIP codes in decile 1 of the share of returns reporting a net capital gainPeriod2016 to 2020SourcePrecinct votes on census geographies to 7.57.5 points of two-party margin swing, toward the RepublicansEstimandvote-weighted mean swing of the lowest decile without the ZCTAs at exactly 0%, shown as a size (95% interval clustered on county)Interval95% CI 5.8 to 9.1n1,310Weightsvotes cast in the ZIP code in 2020 (pres_tot_2020)PopulationZIP codes in the lowest decile of the capital-gains share, leaving out those with exactly 0%Period2016 to 2020SourcePrecinct votes on census geographies points toward the Republicans for capital gains and from 6.36.3 points of two-party margin swing, toward the DemocratsEstimandvote-weighted mean swing of the decile, shown as a size (95% interval clustered on county)Interval95% CI 5.5 to 7.2n2,715Weightsvotes cast in the ZIP code in 2020 (pres_tot_2020)PopulationZIP codes in decile 1 of the share of returns claiming the earned income tax creditPeriod2016 to 2020SourcePrecinct votes on census geographies to 6.46.4 points of two-party margin swing, toward the DemocratsEstimandvote-weighted mean swing of the lowest decile without the ZCTAs at exactly 0%, shown as a size (95% interval clustered on county)Interval95% CI 5.5 to 7.3n1,471Weightsvotes cast in the ZIP code in 2020 (pres_tot_2020)PopulationZIP codes in the lowest decile of the EITC share, leaving out those with exactly 0%Period2016 to 2020SourcePrecinct votes on census geographies points toward the Democrats for the EITC.
The capital-gains result cannot be resolved by more controls. The share correlates +0.81+0.81 correlation coefficient, from −1 to +1Estimandcorrelation of the capital-gains share with the college share (the ZIP-code college variable, whose definition is unresolved) (vote-weighted; 95% interval from a bootstrap of counties, 2,000 replicates)Interval95% CI 0.79 to 0.82n27,144Weightsvotes cast in the ZIP code in 2020 (pres_tot_2020)PopulationZIP code tabulation areas in the contiguous states with more than 100 votes in 2020 and complete IRS and ACS measuresPeriod2016 to 2020 swing; IRS tax year 2022; ACS 5-year estimatesSourcePrecinct votes on census geographies with the college share, the ZIP-code college variable has no resolved definition, and the county results with the bachelor's share carry intervals that include zero, so the data cannot say how much of the capital-gains association is capital gains and how much is education. Every ZIP-code coefficient with the college share held fixed, including the negative capital-gains coefficient and the EITC coefficient near zero, is an adjustment for a variable whose coding is unresolved: if it counts some college or more, the adjustment removes a broader educational gradient than a four-year degree would. The results also depend on the weights. Figure 9 gives the partial correlation of the swing with each share under vote weights and with each ZIP code counted equally. The signs of the capital-gains partial correlation with the college share held fixed and of the EITC partial correlation with the full set held fixed differ between the weightings; the capital-gains partial correlation with the full set held fixed is negative under both.
Figure 9
Two of the partial correlations change sign when every ZIP code counts equally
Partial correlation of the 2016 to 2020 swing with each share, with vote weights and with every ZIP code counted equally; ZIP-code sample
| Share | Controls | Partial correlation, vote weights | Partial correlation, each ZIP code equal |
|---|---|---|---|
| Capital-gains share | No controls | +0.33 | +0.35 |
| Capital-gains share | College share held fixed | −0.09 | +0.04 |
| Capital-gains share | Poverty, college, Black and Hispanic shares held fixed | −0.26 | −0.05 |
| EITC share | No controls | −0.47 | −0.38 |
| EITC share | College share held fixed | −0.22 | −0.18 |
| EITC share | Poverty, college, Black and Hispanic shares held fixed | +0.02 | −0.04 |
Show data
| Share | Controls | Vote weights | Lower bound | Upper bound | Each ZIP code equal | Lower bound | Upper bound | ZIP codes |
|---|---|---|---|---|---|---|---|---|
| Capital-gains share | No controls | +0.330 | +0.288 | +0.376 | +0.345 | +0.318 | +0.374 | 27,144 |
| Capital-gains share | College share held fixed | −0.093 | −0.145 | −0.038 | +0.037 | +0.010 | +0.063 | 27,144 |
| Capital-gains share | Poverty, college, Black and Hispanic shares held fixed | −0.258 | −0.296 | −0.214 | −0.051 | −0.078 | −0.021 | 27,144 |
| EITC share | No controls | −0.475 | −0.520 | −0.431 | −0.381 | −0.410 | −0.353 | 27,144 |
| EITC share | College share held fixed | −0.222 | −0.289 | −0.158 | −0.179 | −0.215 | −0.143 | 27,144 |
| EITC share | Poverty, college, Black and Hispanic shares held fixed | +0.021 | −0.051 | +0.085 | −0.042 | −0.067 | −0.017 | 27,144 |
The wealth measures are narrow. The survey has stock ownership and home ownership as yes or no items, so neither measures the size of holdings. The vote in the survey is self-reported, and the intervals treat the weighted sample as a simple random sample. Chapter 13.1, Measures of hardship compared puts hardship measures on one specification.
Data sources
- Precinct votes on census geographiesPrecinct votes allocated to ZIP code tabulation areas, contiguous states, 2016 and 2020 (Fekrazad 2025, RLCR), joined to the project's ZIP-code demographic file (ACS-based; release not recorded)Years: 2016 and 2020 (contiguous United States only) · Weights: 2020 votes in each ZIP code (pres_tot_2020); ZIP codes with 100 or fewer votes dropped · License: CC0 (data doi:10.7910/DVN/Z8TSH3), as stated in the project README.
- IRS SOI ZIP code dataIRS Statistics of Income ZIP-code data, tax year 2022: share of returns claiming the earned income tax credit, share reporting a net capital gain, mean effective tax rateYears: Tax year as distributed with the ZCTA atlas file. · Weights: none (administrative counts by ZIP code); ZIP codes weighted by 2020 votes in the analysis · License: See the provider's terms of use.
- County election returnsCounty presidential returns, 2016 and 2020, repaired file; the county swing and the county weightsYears: President 1868-2024 (40 elections); House and Senate 1990-2024 · Weights: none (full counts); county estimates weighted by 2020 two-party votes · License: The Heideman file is CC BY 4.0 (doi:10.5281/zenodo.22976553), but the state records behind it keep their own terms, and the sites of Florida, Indiana, Colorado and Wisconsin restrict reuse.
- County demographics panelCounty demographics panel, 2020 election-year row: bachelor's share, poverty, Black and Hispanic sharesYears: 2000-2024 (election years, interpolated between census and survey anchors) · Weights: none (full counts and interpolated estimates) · License: US government source data, public domain. The interpolated panel is derived work.
- Cooperative Election StudyCooperative Election Study, 2016 and 2020: investor and homeowner items and college degree, respondents who voted for one of the two major partiesYears: 2006-2024 (every year; self-reported turnout is available in the 10 even years) · Weights: post-election weight (weight_post) · License: See the provider's terms of use.
Methods
Sample. ZIP code tabulation areas (ZCTAs) in the contiguous states with vote estimates for 2016 and 2020, kept when they have more than 100 votes in 2020, both IRS shares, a swing, the average tax rate and the four ACS controls; this common sample of 27,144 ZCTAs in 3,088 counties is used for every ZIP-code estimate. County sample: 3,113 counties with returns in 2016 and 2020 (Alaska excluded), of which 3,080 have ZIP-code shares and county demographics. The sample table in the last section gives the counts at each step. Votes and outcome. Precinct returns allocated to ZCTAs by the RLCR method (2016 from VEST, 2020 from MEDSL), fractional counts; the allocation reproduces the national two-party Democratic share of 51.09% in 2016 and 52.24% in 2020. The outcome is the swing, the 2020 two-party margin minus the 2016 margin, Democratic minus Republican, in points, so a positive swing is toward the Democrats. The county swing comes from certified county returns. Measures. The share of returns claiming the earned income tax credit and the share reporting a net capital gain (IRS Statistics of Income ZIP-code data, tax year 2022, a year recorded in the project's build code and not in the data file) and the mean effective tax rate; the poverty rate, Black share, Hispanic share and college share from the ACS 5-year estimates in the project's ZIP-code demographic file, dated March 2025, which records neither the ACS release nor the table behind each variable, so these controls are undated. The county controls are the 2020 row of the county demographics panel. The definition of the ZIP-code college variable is unresolved. The file describes it as the percentage of the population with a college degree or higher and names no table, age group or release, but aggregated to counties it averages 52.7% against 23.6% for the county bachelor's share (correlation +0.86), so its level is far above a bachelor's share. The level and the correlation do not establish what the variable counts, so the chapter calls it the college share and leaves its coding open. Weights. ZIP-code estimates are weighted by 2020 votes in the ZCTA and county estimates by 2020 two-party votes. CES estimates use the post-election weight. Correlations and partial correlations are also computed with every ZIP code (or county) counted equally. Estimator. For each share, a weighted least squares regression of the swing on the share and the named controls, every variable standardized on the sample with the same weights, so the coefficient is points of swing per standard deviation of the share. Each set of controls is a separate model, and the full set (poverty, college, Black and Hispanic shares) does not include the average tax rate. Intervals and clustering. 95% intervals use cluster-robust (CR1) standard errors clustered on county for ZIP-code models and on state for county models (t distribution with the number of clusters minus one degrees of freedom). As a sensitivity check the ZIP-code ladder and the decile means are also computed with clusters on state (49 clusters: the states and the District of Columbia); this moves the two capital-gains intervals that hold the college share fixed, with and without the tax rate, to include zero and leaves the other ladder intervals on the same side of zero. Neither clustering allows for dependence between neighboring states. Correlations use a seeded bootstrap of whole clusters (2,000 replicates, seed 12345); decile means use the clustered ratio estimator; CES margins use the Kish effective sample size and a normal interval, which is model based and treats the weighted sample as a simple random sample. Suppression. ZCTAs with 100 or fewer votes are dropped; no survey cell rests on fewer than 30 respondents. Decile groups hold equal numbers of ZCTAs. The 2016 and 2020 survey samples are separate cross-sections, and voters who report neither owning nor renting are left out of the homeowner comparison.
References
- Fekrazad, Amir (2025). A dataset of US precinct votes allocated to Census geographies with precision. Scientific Data 12: 794. doi:10.1038/s41597-025-05140-3
- Voting and Election Science Team (2018). 2016 Precinct-Level Election Results. Harvard Dataverse. doi:10.7910/DVN/NH5S2I
- Baltz, Samuel; Agadjanian, Alexander; Chin, Declan; Curiel, John; DeLuca, Kevin; Dunham, James; Miranda, Jennifer; Phillips, Connor Halloran; Uhlman, Annabel; Wimpy, Cameron; Zárate, Marcos; Stewart III, Charles (2022). American election results at the precinct level. Scientific Data 9: 651. doi:10.1038/s41597-022-01745-0
- Gethin, Amory; Martínez-Toledano, Clara; Piketty, Thomas (2022). Brahmin Left Versus Merchant Right: Changing Political Cleavages in 21 Western Democracies, 1948-2020. Quarterly Journal of Economics 137(1): 1-48. doi:10.1093/qje/qjab036
- Gelman, Andrew; Park, David; Shor, Boris; Bafumi, Joseph; Cortina, Jeronimo (2008). Red State, Blue State, Rich State, Poor State: Why Americans Vote the Way They Do. Princeton University Press.
- Robinson, W. S. (1950). Ecological Correlations and the Behavior of Individuals. American Sociological Review 15(3): 351-357.
How to cite
@misc{singh2026wagescapitalandthecountyvote,
author = {Singh, Vishal},
title = {Wages, capital and the ZIP code vote},
year = {2026},
url = {https://vishalsingh.org/politics/wages-capital-and-the-county-vote},
note = {In The Public Mind. Published 30 September 2026.}
}Same question at another grain
These chapters take up the same axis with a different unit of analysis: individuals, places or countries.
- Income
- Chapter 3.3, The income ladder Individuals
- Chapter 12.3, Income and the county vote (planned) Places
- Chapter 8.7, System justification (planned) Countries