Public enforcement of private child support obligations transfers income from nonresident parents to resident parents (mostly mothers) or, if the mother is receiving welfare, to the state. This paper reviews and synthesizes existing literature on the effects of this transfer of income and presents new empirical evidence on the effects of stronger enforcement on the incomes of mothers and their children. Findings show that more stringent child support enforcement increases the labor supply of mothers who would otherwise have been on welfare, increases slightly or has no effect on the labor supply of nonresident fathers, decreases divorce and nonmarital births, and decreases remarriages of both mothers and fathers. Empirical estimates indicate that stronger child support enforcement increases the income of single mothers and their dependent children by two dollars for each dollar of child support received by single mothers. This implies that the dominant effect of additional child support is to encourage welfare participant single mothers to leave welfare and enter the labor market. This suggests that child support enforcement, in terms of breadth of legislation and administrative expenditures, has an impact on the income of eligible women. (Contains 53 references.) (SM)