Abstract

In this paper, we measure the evolution of the task and skill content of occupations in the US between 1960 and 2000, and quantify its implications for earnings inequality. We construct a new dataset, drawing on a rich and largely untapped source of data: the text content of newspaper job ads. A previous literature has found that over this 40 year period, the employment share of occupations centered around offshorable and routine tasks (especially routine manual tasks) has declined, while the employment share of jobs with non-routine interactive tasks has increased. We document that the evolution of the skill and task content of occupations themselves is at least as important as the employment shifts across occupations in accounting for aggregate changes in
skill and task use. Motivated by these patterns, we decompose changes in the earnings distribution. We find that our new measures, which allow the task and skill content of occupations to vary through time, can help explain a substantially greater proportion of inequality than previous research has found. Changes in the task and skill content of jobs account for a 17 percentage point increase in 90-10 male earnings inequality.