Estimates in this report for 1980 are based on adjustment of sample results to independent estimates of the civilian noninstitutional population derived from the 1980 Decennial Census. Reports for income years 1971 through 1979 used population estimates based on the 1970 Decennial Census. Previously published data for 1979 have been revised using the 1980 census population counts in order to make these data comparable with the new estimates. These revised figures are shown in tables 1, 2, 8, 9, and 16. All references to changes between 1979 and 1980 are based on comparisons of the revised 1979 estimates. Details concerning the introduction of the 1980 Census population figures can be found in the section, "Introduction of 1980 Decennial Census Population Controls."
The average American family experienced a significant decline in real income between 1979 and 1980, according to results of the March 1981 Current Population Survey (CPS) conducted by the Bureau of the Census. The 1980 median family income of $21,020 was 7.3 percent higher than the 1979 median, however, a 13.5-percent increase in consumer prices between 1979 and 1980 caused a net decline of 5.5 percent in real median family income.1 This represents the first statistically significant annual decline in real median family income since 1974-75 and the largest decline recorded in the post-World War II period. The sluggishness of real income growth during the last decade (figure 1) is evidenced by the fact that 1980 median family income was about $1,330 lower than the 1973 median ($22,350) in constant dollars.2
Accompanying the sharp decline in real median family income was an increase of 3.2 million persons below the poverty level between 1979 and 1980.3 This was one of the largest annual increases in the number of poor since 1959, the earliest year for which poverty statistics have been computed. There were 29.3 million persons below the poverty level in 1980, constituting 13.0 percent of the U.S. population. The poverty threshold for a nonfarm family of four was $8,414 in 1980.
1 The percentage increase in prices between 1979 and 1980 is computed by dividing the annual average Consumer Price Index (CPI) for 1980 by the annual average value of the CPI for 1979. See table A-1 of appendix A for CPI's from 1947 to 1980.
2 Throughout this report "constant dollars" refers to dollars in 1980 purchasing power.
3 See appendix A for an explanation of the poverty concept.
Census statistics date back to 1790 and reflect the growth and change of the United States. Past census reports contain some terms that today’s readers may consider obsolete and inappropriate. As part of our goal to be open and transparent with the public, we are improving access to all Census Bureau original publications and statistics, which serve as a guide to the nation's history.