We use data from the 1979 cohort of the National Longitudinal Survey of Youth to estimate the effects of policy and labor market variables on the demographic behaviors that determine children's family structure experiences: union formation and dissolution, and fertility. Male and female wages have substantial effects on family structure for children of black and Hispanic mothers. The tax treatment of children also affects family structure. Welfare reform, welfare benefits, and unilateral divorce had much smaller effects on family structure for the children of this cohort of women. Trends in wages and tax rates explain only a small share of the observed changes in family structure in recent decades. (JEL J12)