Social effects in employer learning: An analysis of siblings

This paper examines whether wages are based on information about personal contacts. I develop a theory of labor markets with imperfect information in which related workers have correlated abilities. I study wage setting under two alternative processes: individual learning, under which employers observe only a worker's own characteristics, and social learning, under which employers also observe those of a relative. Using sibling data from the NLSY79, I test for a form of statistical nepotism in which a sibling's performance is priced into a worker's wage. Empirically, an older sibling's test score has a larger impact on a younger sibling's log wage than a younger sibling's test score has on an older sibling's log wage. The estimates provide strong support for social effects in employer learning.