Children or Migrants as Public Goods?

Why, and to what extent, must taxpayers share the costs of raising children with parents? The most influential argument over this question has been the public goods argument: Taxpayers must share costs with parents because and to the extent that child-rearing contributes toward public goods by helping to develop valuable human capital. However, political theorists have not examined the public goods argument in a context in which replacement migration is available: If replacement migration can provide valuable human capital more efficiently than child-rearing, can the public goods argument still justify a taxpayer obligation to share the costs of child-rearing? This article argues that there are importantly different versions of the public goods argument, and that on a plausible version of that argument, it can withstand the replacement migration challenge under most circumstances.