We analyze potential labor supply effects of a shift from the current German system of joint taxation of married couples to a system of limited real income splitting on the basis of an econometric household labor supply model embedded in a tax-benefit model. Our simulation results show relatively small labor supply effects of a shift from the current system to one of limited real income splitting system. In the benchmark scenario of a shift to separate taxation labor supply of wives would increase substantially in west Germany, while a significant number of husbands would drop out of the labor force.