The design of welfare programs in an era of reform and devolution to the states must take into account the likely effects of programs on demographic behavior. Most research on welfare in the past has examined labor market issues, although there have also been some important evaluations of the effects of the Aid to Families with Dependent Children Program on out-of-wedlock childbearing. Much less information is available on other issues equally central to the debate, including effects on abortion decisions, marriage and divorce, intrafamily relations, household formation, and living arrangements. This volume of papers contains reviews and syntheses of existing evidence bearing on the demographic impacts of welfare and ideas for how to evaluate new state-level reforms.