I am reviewing IPUMS USA, and was wondering if it is possible to obtain county level data for the variables. For example, if I were to select the INCTOT (Total Personal Income) and COUNTY (County) variables, would IPUMS populate this data point for all counties in the US? Thank you!
In IPUMS, the lowest level of geography is PUMA, Public Use Microdata Area (https://usa.ipums.org/usa-action/vari…), an area of about 100K people of general population. Some counties are larger than that, and are broken into PUMAs – and then the county variable would be nonmissing (if you know PUMA, you can match the county to it). Most counties are smaller than 100K though, and are suppressed to protect confidentiality of respondents.
If you need the data by county, you would need to use FactFinder (see e.g. the table of age and sex: https://factfinder.census.gov/bkmk/ta… in this URL, S01001 is the name of the table, 0100000US is all of the US, and 050 is the selection of geographic level = county, as far as I can tell; 16_5YR is obviously the 2012-2016 5-year ACS data product) or data.census.gov that is supposed to understand approximately human queries (although of course “age by sex by county” gives you all sorts of stuff except S0101 table; the direct URL, https://data.census.gov/cedsci/results/tables?q=s0101&g=0100000US:0100000US.050000&tab=ACSST5Y2016.S0101&ps=banner*show@false, shows a structure similar to that of FactFinder though… and the table does not actually get displayed. How the Census is expecting to phase out FactFinder in 2018 in favor of data.census.gov is beyond me.)
Unfortunately, comprehensive county level data is not available from 1950 onwards. So if you are interested specifically in INCTOT, which is only available from 1950 onwards, the answer is no, you would not be able to get data for all counties in the US.
This spreadsheet provides a list of counties and their corresponding ICPSR and FIPS codes available in each year from 1950 onwards.
However, if you are interested in samples prior to 1950, if another variable of interest is also available, you can obtain data for all counties in the US.
Alternatively, you can also look into using IPUMS NHGIS. IPUMS NHGIS provides spatially aggregated census data: data summarizing individuals within particular areas, such as states or counties. Tables are pre-made, but full county level data is available for a variety of topics/years.