Despite numerous studies on labor supply, the size of elasticities is rarely comparable across
countries. In this paper, we suggest the first large-scale international comparison of
elasticities, while netting out possible differences due to methods, data selection and the
period of investigation. We rely on comparable data for 17 European countries and the US, a
common empirical approach and a complete simulation of tax-benefit policies affecting
household budgets. We find that wage-elasticities are small and vary less across countries
than previously thought, e.g., between .2 and .6 for married women. Results are robust to
several modeling assumptions. We show that differences in tax-benefit systems or
demographic compositions explain little of the cross-country variation, leaving room for other
interpretations, notably in terms of heterogeneous work preferences. We derive important
implications for research on optimal taxation.