We estimate how labor force participation among married women in Sweden responded to changing work incentives implied by a reform in the tax/transfer‐system in 1997. Using rich, population‐wide, administrative data we estimate an average participation elasticity of 0.13, thereby adding to the scarce literature estimating participation elasticities using quasi‐experimental methods. We also highlight that estimated extensive margin responses necessarily are local to the observed equilibrium. Among low‐income earners, elasticities are twice as large in the group with the lowest employment level as compared to the group with the highest employment level.