In processing the data collected in the March 1976 Current Population Survey, the Bureau of the Census utilized a new computer processing system designed to take maximum advantage of the Bureau's expanded computer capabilities. The revised system also incorporates many improvements in the procedures used to process the data. A detailed discussion of these improvements and the subsequent revisions to the 1974 income data (for comparability with 1975 data) is provided in a later section, entitled "Revised 1974 Money Income Statistics."

As indicated in the advance report on income, the 1975 median family income of $13,720 represented an increase of 6 percent over the revised 1974 median. However, after adjusting for the 9 percent increase in prices between 1974 and 1975,¹ the 1975 median family income in terms of constant dollars decreased by $360 or about 3 percent. Unrelated individuals had a median income of $4,880 in 1975, also about 3 percent (or $140) lower in real terms than the revised 1974 median.

The decline in real median income reflected the continued sluggishness in the economy during 1975, as evidenced by a decline of 2 percent in the real Gross National Product between 1974 and 1975.² During the same period, the average annual unemployment rate for the nation increased from 5.6 percent in 1974 to 8.5 percent in 1975.³ The rise in the unemployment rate was also accompanied by an increase in the number of persons who exhausted their unemployment benefits, from about 2.0 million in 1974 to 4.3 million in 1975.⁴

Although real median income for all families declined between 1974 and 1975, the data do not indicate uniform movement in median income by race and ethnic origin. White families had a median income of $14,270 in 1975, which represented a constant dollar decline of 3 percent below their revised 1974 median. The median income of Black families ($8,780 in 1975) showed no statistically significant change in real terms. Sampling variability, however, was too large to reliably determine whether there was an actual difference between the percentage changes in median income for Black and White families. Families with a head of Spanish origin had a median income of $9,550 in 1975, a decline in real terms of 8 percent below their 1974 median.

The 1975 median incomes of families in the Northeast ($14,480) and North Central ($14,540) regions represented decreases in real terms of 5 percent and 3 percent, respectively. Median income in 1975 of families in the South ($12,240) and West ($14,320) regions showed no statistically significant changes in real terms.⁵

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¹ The percentage increase in prices between 1974 and 1975 is computed by dividing the annual average Consumer Price Index (CPI) for 1975 by the annual average value of the CPI for 1974.
² U.S. Department of Commerce, Bureau of Economic Analysis, Survey of Current Business, Volume 56, Number 7, July 1976, p. 1.
³ U.S. Department of Labor, Bureau of Labor Statistics, Employment and Earnings, Volume 23, Number 1, July 1976, p. 19.
⁴ Data were obtained from the U.S. Department of Labor, Employment and Training Administration, Office of Administration and Management.
⁵ The decline in real median income of families in the North Central region was not statistically different from the changes in real median income experienced by families in the other three regions.