Chance, Child Traits, and Choice of Family Size

Uses a model of maximization of expected utility, where utility depends on the number and traits of children, as well as consumption. The model is applied to the case when the sex of children is the relevant trait of children to explore questions of family size. The model generates qualitative predictions linking sex composition of children to the propensity to have more children. It is expected that families with either a larger or smaller proportion of boys than they desire or expect in the next birth tend toward larger families than those whose experience conforms more closely to the desired and expected composition. In cases where families modify the expected sex of children in light of the sex composition of their own children, this result depends on the assumption that the demand for children has a price elasticity lower than unity. Data for the United States and East Pakistan are consistent with these predictions. The same theoretical framework is applied to infant survival.