2021, Paper: "This paper provides a distributional analysis of the Tax Cuts and Jobs Act (TCJA), with implications for American households from changes to the individual income and corporate income taxes. We model the impact on average tax rates and after-tax incomes using tax records data from the 2011 Internal Revenue Service public use file and the open-source Tax-Calculator microsimulation model. We find that the effects of the TCJA vary widely across and within income deciles depending upon family structure, the choice of equivalence scales, and whether the impacts are short term or long term. When appropriately accounting for differences in tax unit size, through 2025 the individual income tax changes of the TCJA appear progressive. Failing to account for these differences obscures these progressive effects because larger families benefiting from the expansion of the child tax credit have higher incomes. Combining individual income and business tax provisions in the static scenario, the TCJA is likely to result in short-term increases in after-tax incomes across all deciles, with longer-term decreases for the lower-income households if the individual income tax provisions are allowed to expire. Even in the short run, the gains are significantly lower for those below the top decile. In the long-run dynamic scenario, the TCJA appears regressive, with income gains skewed toward the top."

HKS MRCBG Senior Fellow - Aparna Mathur