Abstract
Abstract Joint taxation can exacerbate the deadweight loss of taxation due to labor supply responses, but evidence is scarce. I estimate the labor supply effects and efficiency costs of joint taxation in the United States by leveraging tax variation created by federal same-sex marriage recognition following the 2013 United States v. Windsor Supreme Court ruling. I estimate significant compensated elasticities along the extensive, but not intensive, margin among both higher and lower earners. My findings suggest that joint taxation is less efficient and generates less tax revenue than individual taxation, and that lowering tax rates for secondary earners could improve efficiency.