We document contemporaneous differences in the aggregate labour supply of married couples across seventeen European countries and the U.S. Based on a model of joint household decision making, we quantify the contribution of international differences in non-linear labour income taxes and consumption taxes to the international differences in hours worked in the data. Through the lens of the model, taxes, together with wages and the educational composition, account for a significant part of the small differences in married men’s and the large differences in married women’s hours worked in the data. Taking the full non-linearities of labour income tax codes, including the tax treatment of married couples, into account is crucial for generating the low cross-country correlation between married men’s and women’s hours worked in the data, and for explaining the variation of married women’s hours worked across European countries.

Abstract We document two robust features of the cross-sectional distribution of usual weekly hours and hourly wages. First, usual weekly hours are heavily concentrated around 40 hours, while at the same time a substantial share of total hours come from individuals who work more than 50 hours. Second, mean hourly wages are nonmonotonic across the usual hours distribution, with a peak at 50 hours. We develop and estimate a model of labor supply to account for these features. The novel feature of our model is that earnings are nonlinear in hours, with the extent of nonlinearity varying over the hours distribution. Our estimates imply significant wage penalties for people who deviate from 40 hours in either direction, leading to a large mass of people who work 40 hours and are not very responsive to shocks. This has important implications for the role of labor supply as a mechanism for self-insurance in a standard heterogeneous-agent incomplete-markets model and for empirical strategies designed to estimate labor supply parameters.

We quantify the disincentive effects of elements of joint taxation in the labor income tax codes of 17 European countries and the US. We analyze the extent to which hours worked of married men and women would change if each country switched to a system of separate taxation of married couples. In this hypothetical tax reform, we keep the average tax burden of married households constant. With the exception of four countries featuring already a system of separate taxation, the model predicts that married women's hours worked increase on average by 115 hours, or 10.5 percent, through this reform.

This paper builds a new internationally comparable database of hours worked to measure how hours vary with income across and within countries. We document that average hours worked per adult are substantially higher in low-income countries than in high-income countries. The pattern of decreasing hours with aggregate income holds for both men and women, for adults of all ages and education levels, and along both the extensive and intensive margin. Within countries, hours worked per worker are also decreasing in the individual wage for most countries, though in the richest countries, hours worked are flat or increasing in the wage. One implication of our findings is that aggregate productivity and welfare differences across countries are larger than currently thought. (JEL E23, E24, J22, J31, O11, O15)