Provisional evaluation of the 1970 census count of American Indians.

Estimates of the American Indian population under 20 years of age on April 1, 1970, based on birth and death statistics for a 20-year period, show a possible net undercount of 6.9 percent for this age group in the 1970 census. However, for some particular ages the estimates indicate net overcounts in the census. Likewise, the net increase of the entire American Indian population as measured by the difference between the 1960 and 1970 censuses is 67,000 greater than the natural increase for the decade. Detailed analysis of cohort data with respect to the possible causes of the differences between the estimates and the census figures indicate that a portion of the estimated net overcounts can be attributed to classification, as well as coverage, problems. The estimated net overcounts offer support for the hypothesis that many individuals who were registered as white at birth and who were counted as white in the 1960 census shifted their racial self-identification from white to American Indian during the 1960's.