Census of Population and Housing, 1990 [United States]: Modified Age/Race, Sex, and Hispanic Origin (MARS) State and County File (ICPSR 9878)

Principal Investigator(s): United States Department of Commerce. Bureau of the Census


The MARS file contains modified race and age data based on the 1990 Census. Both race and age are tabulated by sex and Hispanic origin for several layers of geography. The race data were modified to make reporting categories comparable to those used by state and local agencies. The 1990 Census included 9,804,847 persons who checked the "other race" category and were therefore not included in one of the 15 racial categories listed on the Census form. "Other race" is usually not an acceptable reporting category for state and local agencies. Therefore, the Census Bureau assigned each "other race" person to the specified race reported by another person geographically close with an identical response to the Hispanic-origin question. Hispanic origin was taken into account because over 95 percent of the "other race" persons were of Hispanic origin. (Hispanic-origin persons may be of any race.) The assignment of race to Hispanic-origin persons did not affect the Hispanic-origin category that they checked (i.e, Mexican, Puerto Rican, Cuban, etc.). Age data were modified because respondents tended to report age as of the date they completed the 1990 questionnaire, instead of age as of the April 1, 1990 Census date. In addition, there may have been a tendency for respondents to round up their age if they were close to having a birthday. Age data for individuals in households were modified by adjusting the reported birth-year data by race and sex for each of the 1990 Census's 449 district offices to correspond with the national level quarterly distribution of births available from the National Center for Health Statistics. The data for persons in group quarters were adjusted similarly, but on a state basis. The age adjustment affects approximately 100 million people. In this file their adjusted age is one year different from that reported in the 1990 Census.

Series: Census of Population and Housing, 1990 [United States] Series

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Study Description


U.S. Dept. of Commerce, Bureau of the Census. CENSUS OF POPULATION AND HOUSING, 1990 [UNITED STATES]: MODIFIED AGE/RACE, SEX, AND HISPANIC ORIGIN (MARS) STATE AND COUNTY FILE. Washington, DC: U.S. Dept. of Commerce, Bureau of the Census [producer], 1992. Ann Arbor, MI: Inter-university Consortium for Political and Social Research [distributor], 1992. https://doi.org/10.3886/ICPSR09878.v1

Persistent URL: https://doi.org/10.3886/ICPSR09878.v1

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Scope of Study

Subject Terms:    age, census data, demographic characteristics, ethnicity, Hispanic origins, household composition, housing, housing conditions, population, race

Geographic Coverage:    United States

Time Period:   

  • 1990

Date of Collection:   

  • 1990

Universe:    All persons in the United States.

Data Type(s):    aggregate data

Data Collection Notes:

Data are provided for counties with state totals. State records can be identified by blanks in the county code field.


Data Source:

personal interviews and self-enumerated questionnaires


Original ICPSR Release:   1993-02-14

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