Productivity has been considered a key element for firms and economies to be more competitive. Several studies on productivity at a microeconomic level have found notable heterogeneity between firms. More concretely, differences in Total Factor Productivity (TFP) between large and small firms...

Theoretical contributions to the literature have stressed the role of human capital in promoting economic growth. However, the empirical exercises have provided mixed evidence on the real effect of such type of capital. Most of the evidence has been obtained by estimating growth equations or...