It is argued that a large number of State interventions mimic the agreements that would occur if children were capable of arranging for their own care and serve to improve the efficiency of families. While regulations raise the welfare of children, they also promote the welfare of parents, or, at least, raise the combined welfare of parents and children. The efficiency perspective implies that the State intervenes when both parties gain or when the gain to children exceeds the loss to parents. Thus, laws punish child abuse, the sale of children, and unauthorized abortions. They provide compulsory schooling, welfare payments to families with dependent children, stringent rules about divorce when children are involved, and minimum ages for marriage. Because parents and children can themselves not always make efficient arrangements and because children are unable to commit to compensation to parents in the future, the State may subsidize schools and training facilities to raise investments in poorer families' children to efficient levels. In addition, the next generation gains enough from public expenditures on children by the current generation to pay social security and other help to the elderly of the current generation; while the next generation still has some profit left over from the public investment of their human capital. 35 footnotes.