I have pulled tract-level 1970 data on sex by age (NT17) with a race/ethnicity breakdown (all races, white, black, and Hispanic). From this set of variables, I am interested in generating mutually exclusive race/ethnicity categories (non-hispanic white, non-hispanic black, non-hispanic other, and hispanic of all races) for each age group. To do this, I am attempting to impute the racial breakdown of Hispanic people in a given age group for each tract in my study area. The best way I can think to do this is to impute the racial categories of Hispanics within a given age group using tract-level data on the portions of Hispanics of all ages that are identified with each racial group.
The only table that breaks down the racial identifications of Hispanics in the 1970 census at the tract level looks like NT24 (Spanish Indicator). However, as I learned from Jonathan’s answer to a past forum post (1970 Hispanic indicator?), the categories in NT24 are not mutually exclusive. Jonathan said that NHGIS time series tables generally use the C11001 category to identify Hispanics in a way that somewhat more consistent with other Censuses.
However, I’m noticing that there are tracts for which the C11001 count (people of all races self-identifying as Hispanic on the origin or descent question) in table NT24 is 0, but there are nonzero counts of Hispanics in specific age groups in the NT17 table (the C1UAC variables). I assume this means that the Hispanic variables in the NT17 table include a wider set of people than just those who are identified as Hispanic using the origin or descent question, and I confirmed that the tracts in question do have nonzero counts for other Spanish Origin indicators like C11002 (Puerto Rican birth or parentage) or C11003 (Spanish language). I am wondering what set of Spanish Origin indicators results in people being considered Hispanic in table NT17? Perhaps this is related to the way that the HISPAN variable is imputed for 1970 microdata? (1960 Census: Hispanic Status)
If the Hispanic breakdown for the NT17 table consists of all people for whom one or more Spanish Origin indicator applies, than I am wondering how I might go about getting tract-level data on the racial composition of those people. Table NT24 does not seem to have a variable that breaks down the racial identifications of all people for whom any Spanish Origin indicator applies - only the breakdowns for individual Spanish Origin indicators.