Taking Selection to Task: Bounds on Trends in Occupational Task Prices for the U.S., 1984-2013

In the large literature on polarization in the wage and employment structure, arguments about shifts in relative demands for different task based groups have been built on comparisons of movements in employment and wages. In particular, increases in both wages and employment in cognitive task occupations relative to routine task occupations are the basis for arguments that Information Technology innovations are driving labor market polarization. But movements in average wages by occupation are misleading measures for determining underlying demand forces for two reasons. First, the workforce has undergone substantial compositional changes in terms of education levels, the age distribution, and the gender composition. Second, it seems reasonable to assume that the large shifts in the proportion of workers in different occupations has been accompanied by shifts in composition in terms of unobservable task related abilities. In this paper, we provide estimates of movements in task prices for the US for the period from 1984 to 2013. To do this, we adjust for changes in observable variable composition and address selection on unobservables through a bounding exercise. We