Abstract
Married couples file joint tax returns in many European countries. Nevertheless, research quantifying the effect of joint taxation on the work incentives of secondary earners is scarce thanks to a lack of recent policy changes.
This study makes use of the introduction of joint taxation in the Czech Republic in 2005 to estimate its effect on married women's labor supply. Results based on difference-in-differences and on triple differences with several alternative control groups suggest that the introduction of joint taxation lead to a decline of about 3 percentage points in the employment rate of married women with children.
Participation declines are twice as large when the tax work disincentives are highest-among women with high-income husbands.