With Friends Like These: Endogenous Labor Market Segregation with Homogeneous, Nonprejudiced Agents

In the economics literature, labor market segregation is typically assumed to arise either from prejudice (Becker 1971) or from group differences in human capital accumulation (Benabou 1993; Durlauf 2006; Fryer 2006). Many sociological studies, by contrast, consider social network structure as an embodiment of various forms of social capital, including the creation of obligations, information channels, and enforceable trust (Coleman 1988; Portes and Sensenbrenner 1993). When firms hire by referral, social network segregation can lead to labor market segregation (Tilly 1998). Various social network structures may arise from the actions of self‐interested individuals (Watts and Strogatz 1998; Jackson 2006); by incorporating concepts of social capital into an economic framework of profit‐maximizing firms, this article develops a model of labor markets in which segregation arises endogenously even though agents are homogeneous and have no dislike for each other. Firms hire through referrals, and can enforce discipline by bribing a referrer to prevent a hiree from getting any outside job offers from other friends if he or she shirks. This is possible only if social networks are reasonably closed, so that the referee knows a majority of his or her friends' friends. By segregating into small communities, workers can more effectively create closed social networks. Social networks with different reservation wages will receive different wages; firms can induce such segregation and wage discrimination in the interest of profit. Workers may not benefit from such segregation, except as a best response to being in a society where it already exists; the “friends” in these social networks act as a worker discipline device, and in this way treat each other inimically.