Explaining the labor share: automation vs labor market institutions

In this paper, we build a theoretical model to study the effects of automation and labor market institutions on the labor share. In our model, firms choose between two technologies: an automated technology and a manual technology. In this context, the labor share reflects both the average wage level (versus output) and the distribution of firms between the two technologies. Our model offers three main insights. First, automation-augmenting shocks reduce the labor share but increase employment and wages. Second, labor market institutions (relative to automation) play an almost insignificant role in explaining the labor share. Third, our model suggests that the US labor share only (clearly) falls after the late 1980’s because of a contemporaneous acceleration of automation’s productivity.