This chapter argues that there is a collective responsibility to have enough children in order to ensure that people will not, in the future, suffer great harm due to depopulation. Moreover, if people stopped having children voluntarily, it could be legitimate for states to incentivize and maybe even coerce individuals to bear and rear children. Various arguments against the enforceability of an individual duty to bear and rear children are examined. Coercing people to have children would come at significant moral cost; however, none of the arguments against enforceability seem decisive. The existence of a collective responsibility to have children bears on the question of whether parents and non-parents ought to shoulder the costs of childbearing and child rearing together.