Rationality and Society, Vol. 19, No. 3, 335-366 (2007) DOI: 10.1177/1043463107080450
2007 SAGE Publications A Model of Social Interactions and Endogenous Poverty Traps Roland G. Fryer, Jr.
Harvard University, rfryer at fas.harvard.edu
This paper develops a model of social interactions and endogenous poverty traps. The key idea is captured in a framework in which the likelihood of future social interactions with members of one's group is partly determined by group-specific investments made by individuals. I prove three main results. First, some individuals expected to make group-specific capital investments are worse off because their observed decision is used as a litmus test of group loyalty . creating a trade-off between human capital and cooperation among the group. Second, there exist equilibria which exhibit bipolar human capital investment behavior by individuals of similar ability. Third, as social mobility increases this bipolarization increases. The model's predictions are consistent with the bifurcation of distinctively black names in the mid-1960s, the erosion of black neighborhoods in the 1970s, accusations of `acting white', and the efficacy of certain programs designed to encourage human capital acquisition.
Key Words: social interactions . group investment . cooperation . human capital . inequality