Income Inequality and Campaign Contributions: Evidence from the 1986 Reagan Tax Cut

Does higher income inequality increase political inequality by raising the political influence of rich donors? We attempt to answer this question by providing evidence of the effects of a policy-induced rise in income inequality on the concentration of campaign contributions in the US. Using a novel dataset at the Census tract level we show that the 1986 Tax Reform Act, which disproportionately benefited wealthy taxpayers, caused a spike in individual contributions, predominantly from donors at the top of the income distribution. The effect was similar for both parties and unrelated to the recipients' ideology or office sought. For members of Congress, the effect was larger for legislators that voted in favour of the tax bill and for candidates likely to be well-connected or from privileged backgrounds. We also find that an increase in disposable income is more likely to induce political donations when the donor and the recipient share a similar social background. Taken together, our results suggest that the effects of tax policy extend beyond the economic domain, with implications for the distribution of political influence through campaign contributions.