This monograph synthesizes findings from five large-scale studies investigating welfare and employment programs in order to examine the effects on children of key policies: providing financial support for working families, requiring single parents to work, and limiting time on welfare. It identifies program features associated with effects on children's school achievement, social behavior, and health. The studies randomly placed parents in either a program group, which had access to new services and benefits and was subject to new rules, or a control group, which received benefits and was subject to previously existing rules. In surveys conducted 2-4 years after parents entered the studies, children's school achievement, social behavior, and health were measured, and a subset of single parents was analyzed. Overall, programs that included earnings supplements for parents who went to work positively affected elementary students, whose academic achievement surpassed that of children in the traditional welfare system. Adding mandatory employment services did not greatly reduce those positive effects. Programs with mandatory employment services and programs with time limits had few effects on children. They did have some negative effects on adolescent behavior and school achievement. The positive effects of earnings supplement programs on children were most pronounced for children of long-term welfare recipients. An appendix presents outcome levels and impacts underlying effect sizes presented in this monograph. (Contains 76 references.) (SM)