Lucas' 1988 model of the external effects of human capital formation is used as a starting point for an analysis of the impact of human capital on wages. Most empirical tests of new growth theory are based on time-series and cross-section data. This paper suggests a microeconometric approach to...

We study the incentives to improve ability in a model where heterogeneous firms and workers interact in a labor market characterized by matching frictions and costly screening. When effort in improving ability raises both the mean and the variance of the resulting ability distribution, multiple...