The poverty estimates compiled from the March 1977 Current Population Survey (CPS) were obtained from an expanded sample of households. This sample consisted of 65,500 housing units, approximately 10,500 more housing units than were used to develop the poverty estimates from the March 1976 CPS. Further discussion of the sample expansion can be found in the section, "New Procedures Used in the March 1977 CPS." In addition, it should be noted that the term "householder" has been used in the text of this report in place of the term "head," which appears in the detailed tables. See the section, "Head versus Householder" for further details.

This report presents detailed social and economic statistics for the propulati0n of the United States below the poverty level in 1976 based on the March 1977 Current Population Survey (CPS). As in previous poverty reports, data are presented by selected characteristics such as race, family status, residence, education, work experience, and type and source of income. For the first time, poverty data for the 20 largest SMSA's and their central cities are included.

The poverty threshold for a nonfarm family of four persons was $5,815 in 1976, about 6 percent higher than the comparable 1975 figure of $5,500. The poverty thresholds are updated every year to reflect changes in the annual average Consumer Price Index (CPI). See page 204 for a detailed explanation of the poverty concept. In this text, the terms ''poverty," "low-income," and "poor" are used interchangeably.