How can I get age distribution data per county (for all counties in USA) for the 1990 Census? I'm new here. Thanks


How can I get age distribution data per county (for all counties in USA) for the 1990 Census? I’m new here. Thanks



Welcome to IPUMS! There are a couple of notes that should be helpful in finding the data you need.

First, age distributions can be calculated by using the AGE variable. This can be found under the Demographic heading under Person-level variables.

Second, counties are actually unavailable in public use data from 1950 onwards. This is due to confidentiality restrictions. Instead, the PUMA (public use microdata area) is the lowest level geographic identifier in modern samples of public use data. However, it is possible to recover some counties when low level geographic identifiers are coterminous with counties. See this spreadsheet for a report of which counties are available in what samples.

Third, IPUMS USA provides microdata (i.e. individual records from the US census). If you are looking to perform an analysis aggregated at the county level, then IPUMS NHGIS may be better suited for your needs. IPUMS NHGIS provides aggregated data that isn’t restricted by confidentiality requirements and thus has information on all counties in the US.

I hope this is helpful. Check out these online tutorials to further familiarize yourself with the tools available through IPUMS. Also, feel free to ask any questions you may have on this forum or to



Hi Jeff, thanks for your reply. I could download age distribution by county for the 2000 Census on the Census website. However, for the 1990 Census, the digital form is not available on the Census website, so they told me to come to this site. I believe that 1990 Census age distribution per county should be available somewhere. I just don’t know how to access it.

The reason why I want county level data is because I need to match county to the 2010 MSA definition in order to match the other variables in my regression. Thank you!



Ok, so it sounds like IPUMS NHGIS may be your best bet. You can select county as your geographic level, 2000 as the year, and age as the topic. This will provide a number of tables to choose from. A popular table is NP012B - Population by Sex by Age.

I hope this is what you are looking for. Let me know if you have any questions.



Hi Jeff,

After I choose county, age, 1990, I got the following tables and I don’t see the table you suggested.

| 1990_STF1 | STF 1 - 100% Data |
| (-) | 1990_STF2a | STF 2a - 100% Detailed Data |
| (-) | 1990_STF2b | STF 2b - 100% Detailed Data with Race/Ethnicity Breakdown |
| (-) | 1990_STF3 | STF 3 - Sample-Based Data |
| (-) | 1990_STF4a | STF 4a - Sample-Based Detailed Data |
| (-) | 1990_STF4b | STF 4b - Sample-Based Detailed Data with Race/Ethnicity Breakdown |
| (-) | 1990_MARS | Modified Age/Race, Sex & Hispanic Origin (MARS) State & County File |



So, I picked the following table and submited, but I haven’t gotten an email from Ipums with the download link. I’m not sure if I’m doing the right thing and also not sure if this table has what I want.

How can I access the table you mentioned? Thanks so much.

1990 Census: STF 2a - 100% Detailed Data

NPA7. Age by Group Quarters Persons in group quarters

Age (3), Household, Family and Group Quarters Type (13)




Yeah, the NHGIS system can be a bit cluncky at times. I’ve attached a zip file with the table I was looking at. (331 KB)



Hi Jeff, I believe the table you sent was for the year 2000. I’m looking for 1990 census data for age distribution by county. Can you send it to me? Thanks.



Hi Jeff, in addition to the age distribution, I tried to download the detailed education attainment data for the year 1990, 2000, 2005-2015. I want the data per metropolitan statistical area (MSA). I want the MSA definition to be the one pre-2013, so there should be 366 MSAs. The file I downloaded ends with dat.gz, but I can’t open it. Following instruction from your website, I downloaded Winzip to try to open it, but it didn’t work. I wonder if you can send me the file in excel. Thanks.



Oh, yes. This was my mistake. The attached file should be what you are looking for. (250 KB)



Hi Jeff, can you please answer my question regarding the education file? Please let me know. Thanks.



Yes, sorry I missed that. We typically recommend 7-zip as a decompression software. We also have some online video tutorials that can help troublshoot these issues. But the basic steps are: (1) unzip the .dat.gz file, (2) open your prefered statistical software and make sure working directories are set up correctly, and (3) run the command file (found on your IPUMS downloads page) corresponding with your statistical software. Everything should work properly. Let me know if you have any questions.



Hi, I’m wondering if you have or know who has the GDP data for the year 2000 by metropolitan statistical areas. It’d be the MSA definition (CBSA2010 definition), so there should be 366 MSAs. (BEA only has it for 2001 onward.) Please let me know as soon as you can. Thanks so much!



This is a good question and one I’m not sure I can answer well. We (IPUMS) don’t have data on GDP. You may want to try reaching out to the BEA. I see an email on one of their reports, listed in a section on data availability, is I hope this helps. I’m sorry I can’t directly answer your question.