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.

Using a broad panel of advanced economies, we document that increases in GDP per capita are associated with a systematic shift in the composition of value added to sectors that are intensive in high-skill labour, a process we label as skill-biased structural change. It follows that further development in these economies leads to an increase in the relative demand for skilled labour. We develop a quantitative two-sector model of this process as a laboratory to assess the sources of the rise of the skill premium in the U.S. and a set of ten other advanced economies, over the period 1977 to 2005. For the U.S., we find that the sector-specific skill neutral component of technical change accounts for 18–24% of the overall increase of the skill premium due to technical change, and that the mechanism through which this component of technical change affects the skill premium is via skill-biased structural change.