The effect of the timing and spacing of births on the level of labor market involvement of married women

We analyze the effect of the timing and spacing of births on the labor supply of married women in a framework that accounts for the endogeneity of the labor market and fertility decisions, for the heterogeneity of the effects of children on labor supply and their correlation with the fertility decisions, and for the correlation of sequential labor market decisions. Delaying the first birth leads to higher pre-natal levels of labor market involvement and reduces the negative effect of the first child on labor supply. The effect of the second child increases with the spacing of the two births as women, returning to work after the first birth, finance child care time increasingly through reductions in market time. Individual heterogeneity is considerable; women with lower propensity for children have the first birth later in life and space subsequent births more closely together, work more before the birth of the first child, but face larger effects of children on their labor supply.