In this article we estimate the long-run aggregate elasticity of substitution between skilled and unskilled workers. This is an important parameter as it allows us to compute the skill biased technological progress (SBTP) from the evolution of relative wages. However, it is hard to estimate...

Identification of the strength of human capital externalities at the aggregate level is still not fully understood. The existing method may yield positive or negative externalities even if wages reflect marginal social products. We propose an approach that yields positive average human capital...