The Political Economy of Joint Taxation

Joint taxation of married couples represents a puzzle for welfare economics. We investigate whether political economy forces can explain its persistence. We develop sufficient statistics to determine whether a reform towards individual taxation would garner majority support and apply this framework to the U.S. tax system since the 1960s. Our findings indicate that support for individual taxation has increased over time. As of today, 50% of all married individuals would benefit from such a reform. Among those worse off are poor single-earner couples. A reform that reduces marriage bonuses also for them is rejected by a social welfare function that concentrates weights at the bottom of the distribution.