Title: Differences in On-the-Job Learning across Firms

Abstract: We present evidence consistent with large disparities across firms in the on-the-job learning their young employees experience, using administrative datasets from Brazil and Italy. We categorize firms into discrete “classes”--which our conceptual framework interprets as skill-learning classes--using a clustering methodology that groups together firms with similar distributions of unexplained earnings growth. Mincerian returns to experience vary widely across experiences acquired in different firm classes. Moreover, past experiences at firms with better on-the-job learning lead to subsequent jobs featuring greater non-routine task content. Our findings hold among involuntarily displaced workers with no seniority at their post-displacement jobs, consistent with a portable skills interpretation. Overall, we show that heterogeneous employment experiences explain an important share of wage inequality by age 35, this share grows with age, and is significantly underestimated if all experiences are instead assumed to be homogeneous. Lastly, we show that firms’ observable attributes only mildly predict on-the-job learning opportunities.