Birth rates are falling worldwide, in every region. Falling birth rates can be decomposed into two components: (1) an increase in childlessness (i.e., lifetime nulliparity), and (2) fewer children ever born to women who have at least one child (completed cohort fertility among the parous). This...

Utilitarianism is the most prominent family of social welfare functions. We present three new axiomatic characterizations of utilitarian (that is, additively separable) social welfare functions in a setting where there is risk over both population size and the welfares of individuals. First, we...