I’m trying to get medicaid use by county for California. However, there are no observations for Santa Clara county (FIPS 6085) after 2005 is there a reason for this, despite there being results for numerous other counties?
After April of 2004, Santa Clara county is no longer identified in the CPS; some counties are not identified to preserve respondent confidentiality. Also, please note that the county code 6085 in the May 2004-July of 2005 is actually San Jose, which is not identified in the data after July of 2005. Santa Clara county is erroneously included in the list of identified counties in August 2005-onward CPS data; this documentation will be updated with the next release. Here is a blog post with more information on missing counties in IPUMS microdata.