In 1990, more than 1 in 5 Americans — or 52 million — lived in a “poverty area.” Poverty areas are census tracts or block numbering areas (BNA’s) where at least 20 percent of residents were poor in 1989. (See the box on page 2 for a definition of census tracts and BNA’s). Just over two-thirds of poverty area residents lived in a metropolitan area. In some of these areas, poverty was especially widespread, as 40 percent or more of residents were poor. About 1 in 25 Americans lived in such a tract or BNA, known as an “extreme poverty area.”