I am trying to merge county level data from ipums that I downloaded (ACS surveys), but it’s not in the fips code. I came across:


However, they don’t seem to have the crosswalk from the ipums data to fips codes? Am I overlooking something?

The variable COUNTYuses the ICPSR coding scheme. While the first three digits are usually identical to the FIPS county codes, ICPSR adds a fourth digit to accommodate change over time. I recommend reading the description and codes pages for COUNTY, as they will contain information about the limitations of the variable as well as links to the codes. If you are not interested in using the ICPSR coding scheme, the variable COUNTYFIPSoffers county information using the FIPS codes.

I hope this helps.

Hi Erica,

Sorry for the delayed reply – didn’t realize you had replied already and I couldn’t find the thread until Tim thankfully clarified to me how to find threads!

I had read the ICSPR description, but was hoping to avoid manually hardcoding the crosswalk. Just to clarify your suggestion – the idea is combine the statefips and countyfips codes to create a unique county code within a year, right? Can I drop the fourth digit that yours adds and just weight regularly, or how would I match the fourth digit over to a regular county level dataset?

Never mind, I think I resolved it based on your initial clarification.

Basically generate county = st*1000 + countyfip