Measuring concentrated poverty: The federal standard vs. a relative standard

How should concentrated poverty be measured? U.S. scholars have almost universally defined it as census tracts in which 40 percent or more of the population falls below the official federal poverty line. This standard, originally based on a minimally acceptable diet, has become increasingly divorced from the realities of our affluent society and ignores differences across metropolitan areas. We use instead a relative definition of poverty based on 50 percent of median income in each region. We find that the extent, geographic distribution, and trends in concentrated poverty between 1990 and 2000 are very different from those found using the federal poverty standard. For a small sample of metropolitan areas, we show that census tracts of relative concentrated poverty, excluded under the federal definition, rank among the most disadvantaged in their areas. We conclude by recommending that researchers studying concentrated poverty supplement the official federal standard with a relative approach.