In “Teenage Sex, Pregnancy, and Nonmarital Births,” Isabel V. Sawhill, a senior fellow at the Brookings Institution, describes recent trends in teenage sex, pregnancy, and nonmarital births. Her main sources of data are the Current Population Survey (CPS) and the Vital Statistics Cooperative Program (VSCP). Sawhill begins by describing the high proportion of children living in single-parent families and showing how this arrangement contributes to child poverty. Between 1970 and 1996, for example, poverty rose from 15 to 20 percent of all children. Virtually all this increase stemmed from the growth of single-parent families. Moreover, a shift in the composition of single parents, so that a greater number are never-married mothers, exacerbated poverty and welfare dependency. In the 1960s and 1970s, the growth in single parenthood was largely attributable to increases in divorce; in the 1980s and 1990s, however, the growth was largely driven by nonmarital births.