Single-person households -- Division of labor in households and families ; Supplement: human capital, effort, and the sexual division of labor -- Polygamy and monogamy in marriage markets -- Assortive mating in marriage markets -- The demand for children -- Inequality and intergenerational mobility ; Supplement: human capital and the rise and fall of families -- Altruism in the family -- Families in nonhuman species -- Imperfect information, marriage, and divorce -- The evolution of the family ; Supplement: the family and the state.