FOR MANY YEARS NOW, economists and policymakers have voiced concern about what is said to be an increasing number of poor people in the United States. Their attention has been focused for the most part on the rise in the measured rate of poverty that has occurred since the early 1970s. According to the estimates of the U.S. Census Bureau, the fraction of the civilian, noninstitutionalized population living below the official “poverty line” underwent sustained and secular increase during most of the 1970s and all of the early 1980s. Between 1973 and 1983, the “poverty rate” rose from 11.1 percent of the population to 15.2 percent, or by well over a third. Though the poverty rate declined somewhat during the subsequent years, it was still placed at 13.6 percent in 1986--higher, both relatively and absolutely, than it had been a decade and a half earlier.