Part-time wage differentials are related to the extent to which part-time workers are concentrated in low-wage occupations. Evidence suggests that much of the wage difference between part-time and full-time workers is explained by differences in workers and jobs, with differences in job characteristics such as occupation or sector being by far more important, and that the wage penalty might be small but rises over the working life, as a result of lower experience levels and accumulated human capital (Hirsch, 2005, Bardasi and Gomick, 2008, OECD, 2010). The under-investment in human capital associated with short-term contracts can give rise to lower wages for temporary workers. Another possibility is that workers accept lower wages with the expectation that this would be followed by more stable careers.