Abstract: When members of a minority group can monitor and constrain each other, they can leverage their internal social capital to financial gain. When they live within dense networks of personal contacts, they will more often have the information necessary to learn whether potential trade partners have kept their word and to punish those who have not. When members of a minority group lack that social capital, they not only lose these advantageous transactions but become vulnerable to their own self-appointed leaders as well. Lacking a network of close ties, they can neither monitor nor constrain others in the group. This vacuum creates an opening for opportunists to purport to act on their behalf (perhaps to obtain ethnic subsidies or other group preferences), but actually to divert rents to themselves--and incite hostility toward the group in the process. Arrovian statistical discrimination and selective out-migration follow. The opportunists raise the level of dysfunction within the group. Faced with an outside majority that treats minority members by the observed group mean, those minority members with the highest outside options will now leave and abandon the group to the opportunists. Any ethnic subsidies will offset the discrimination in part, of course. The higher the level of subsidies, the fewer the number of minority members who will find it advantageous to leave; the higher the level of subsidies, the slower the pace at which the dysfunctional minority will merge into the mainstream I illustrate these dynamics with examples from the burakumin outcastes in Japan, the Korean residents in Japan, and the Okinawans.