Income Taxation of Couples and Gender (In)equality in Earnings (solo-authored)

How does a move from joint taxation to individual taxation affect the gender earnings gap? In Germany, married couples can choose between individual or joint (withholding) income taxation. The 2013 withholding income tax reform introduced individual taxation as the default for newlywed spouses. This implied lower average and marginal tax rates for the secondary earner, typically the wife, if couples stayed with the default. I use unique and novel data for the universe of German taxpayers and leverage the default introduction as an exogenous change to the share of newlyweds choosing individual taxation. I establish three main results. First, the share of newlyweds choosing the individual tax schedule increases by 13.5 percentage points after the default introduction. Second, female labor force participation increases by 1 percentage point. Third, the partner pay gap narrows by 2 percentage points as a result of a rise in pre-tax female labor income, while pre-tax male labor income remains unchanged compared to the period preceding the default introduction. My findings suggest that a move from joint taxation towards individual taxation of spouses can improve gender equality in earnings and raise overall labor supply.

Joint Taxation and Intra-Household Inequality: Evidence from Same-Sex Couples  (with Elena Herold and Carina Neisser)

Joint taxation of couples is often criticized for distorting labor supply and reinforcing household income inequality, particularly by disincentivizing secondary earners. Yet, empirical evidence is limited, as switching to joint taxation is typically endogenous and observed responses among different-sex couples are shaped by gender norms. We study the 2013 extension of joint income taxation to same-sex civil partners in Germany to isolate how tax incentives influence household income allocation. Using administrative tax return data on the universe of filers, we provide the first large-scale evidence on same-sex couples in Germany. We find that joint taxation increases within-couple inequality, primarily through reduced earnings of secondary earners. The partner pay gap rises by 4.1 percentage points - a 12.8% increase relative to the pre-reform level. Estimated tax elasticities are statistically significant but smaller than those for women in different-sex couples. However, they become insignificant when estimated within relative earner groups, suggesting that responses reflect increased inequality within couples rather than individual responses to marginal tax changes. Additionally, we show that same-sex couples are less likely than different-sex couples to choose withholding schemes that reinforce income differences between partners. Our findings suggest that joint taxation increases intra-household inequality, especially when incentives align with gender norms and there is scope for specialization. 

The Impact of Parental Leave Benefits on Pre-Birth Earnings (with Ulrich Glogowsky, Amelie Grosenick, Emanuel Hansen, Andreas Peichl and Dominik Sachs)

Abschaffung der Steuerklassen III und V: Positiver Impuls für den Arbeitsmarkt ohne fiskalische Kosten (mit Andreas Peichl, Nadine Riedel und Ida Zinke)

How Important Are Local Knowledge Spillovers of Public R&D and What Drives Them? (2020), with Martin Simmler, Research Policy, 49(7)