Many economics theories suggest that the assignment of workers to occupations changes over the business cycle: expansions allow workers to upgrade to occupations that pay higher wages and require more skill. This paper provides some empirical evidence from the USA that such upgrading does occur and that, as predicted, it has greater effects on less-skilled individuals. Furthermore, the skill composition of new hires changes over the business cycle, even within occupations. Consistent with a job competition model, the education levels of new hires within occupations are higher when the unemployment rate is high and this effect is more pronounced in lower-paying occupations. The changes in assignment imply that low-skilled individuals suffer most from recessions in terms of occupation quality and unemployment. The results are consistent with employers responding to a greater supply of educated workers by increasing hiring standards, and so imply that the social return to education may be lower than the private return. However, the results are also consistent with more neo-classical models of the labor market.