Political behavior generates private benefits by helping people Ft in
with desired friends. A voter imitates other voters, but at the same t
ime they imitate him. An equilibrium solution requires exogenous varia
bles: the narrow self-interest of the participants. The reduced form m
akes one's vote a function of the narrow self-interest of others as we
ll as one's own. In accord with the model, a person's party identifica
tion depends on his ethnic group's current income and its income in 19
09 as well as his own income.