I have a version of a 2008-2012 ACS variable topcodes that I downloaded in June 2019. In my download, each state-year observation has its own topcode (5 years x 52 states = 260 observations). However, currently on the ACS topcode webpage, the 5-year ACS topcodes just have one variable per state (rather than one for each year and state). The 2019 version that I have on hand does not seem to match any of the single-year files either, other than 2012. Do you know whether there was an update that occurred at a particular time since 2019 that replaced single-year topcodes with just one value per state for the 5-year ACS?
In the multi-year ACS PUMS files from the Census Bureau, the top- and bottom-codes can be found in the documentation for each data year that makes up the file. For example, in the 2008-2012 5-year ACS, the 2008, 2009, 2010, 2011, and 2012 original PUMS top- and bottom-code documentation files should each be referenced. This is not the case for the IPUMS multi-year datasets, as variables reporting dollar values have been inflated to dollars for the last data year (i.e., 2012 dollars for the 2008-2012 5-year file) resulting in top- and bottom- codes that differ from the single-year ACS documentation. You can find a list of sample-specific top and bottom coded values for ACS/PRCS samples by state here. We do not currently provide a list of inflation-adjusted top and bottom codes for multi-year files.
Hi Isabel, Thanks so much for your response. My question is also about historical versions of these topcodes. In the 2010-2014 5-year ACS excel file at the link you shared (https://usa.ipums.org/usa/volii/top_bottom_codes.shtml), the topcodes each have a different value for each year and state. In the 2008-2012 5-year ACS excel file at the same link, however, there is no variation by year. I am wondering if in the past, the 2008-2012 version did have year-specific values, and if those have been replaced with the single value now. This is because in the prior version of the 2008-2012 file I have on hand from 2019, the values vary by year. I am just wanting to confirm that what I have on hand was from the IPUMS website but it now has been replaced by another version does not vary by year. Thanks so much for your help!
I’m sorry for any confusion and my misunderstanding of your question! This is a good question, and the IPUMS USA team will look into it, hopefully within the next couple of weeks. I will post again here when I have more information to share.
Hi Mary, this is still on our radar and our IPUMS USA team has been looking into it this week. I expect to have more information to share by next week. Thank you for your patience!
Thank you for your patience in awaiting a reply, and my apologies for the delay in getting back to you.
The top and bottom codes files should never have included different values by survey year (MULTYEAR) for IPUMS-provided multi-year ACS samples. IPUMS has always adjusted dollar amount variables in multi-year ACS samples to the last year of the data.
Unfortunately, it sounds like the file you downloaded back in 2019 contained an error. We previously provided top and bottom codes files that reported top and bottom codes that varied by year for multi-year ACS samples, which was incorrect.
Since 2019 we have made changes to the top and bottom codes files that are provided on this page, including a recent update to account for a small change in variable format. I cannot say with certainty whether a concerted effort was made to correct the issue with the multi-year top and bottom codes files specifically, but it sounds like the particular file you downloaded previously was at some point updated to correct that issue.
At the time of your posting on the forum, some of the top and bottom codes files we provided still contained this error, including the 2014 5-year codes file that you referenced. Other files had been corrected, including the 2012 5-year codes file that you referenced. In response to your forum post, we have now fixed the remaining top and bottom codes files. None of the top and bottom codes files for multi-year IPUMS data files include top and bottom codes that differ by year.