Although the vast majority of single mothers do not fit the description of an underclass, there is a small group of predominantly black single mothers concentrated in northern urban ghettos that is persistently weakly attached to the labor force, socially isolated, and reproducing itself. Although welfare programs are necessary for those who are failed by or who fail in (depending upon one's political perspective) the labor market and other mainstream institutions, too heavy a reliance upon welfare can facilitate the growth of an underclass. In contrast, aiding single mothers through more universal programs such as a child support assurance system, child care, health care, children's allowances, and a full employment macro-economic policy will retard the growth of an underclass. (BJV)