Years used to retrieve ACS05-ACS10 Conversion Rates

USA
1

Dear IPUMS Team,

My question refers to the official occupational crosswalk published by the Census, which link ACS05 to ACS10 and ACS12 to ACS18.

Throughout the Census webpage, it is said that such crosswalks were created by dual-coding a sample of occupations from the years preceding coding scheme change.

I would like to know precisely what years were used. For instance, in order to retrieve the ACS05-ACS10 Conversion Rates, was the 2009 ACS double-coded and passed to the ACS10 coding scheme? Or was it a sample of all years ranging from 2005 to 2009?

The reason I am asking this is that, in this link (5-year to 5-year Comparison Guide), the following excerpt can be found: “To allow for the creation of 2006-2010 tables, occupation data in the 2006-2010 multiyear file was recoded to 2010 Census occupation codes”.

However, the IPUMS CPS webpage reads “The Census Bureau does provide a crosswalk to compare the 2002-2010 occupation coding schemes. […] A conversion rate crosswalk that provides these proportions is available for comparing the 2008 and 2010 American Community Survey (ACS)”.

Hence, it is not clear to me exactly which years were used in the dual-coding process; the Census website hints at a mix of years from 2006 to 2010, while the CPS webpage seems to indicate that only the year 2008 was used.

Taking this opportunity, just to be on the safe side, I would also like to ask the same question regarding the ACS12-ACS18 crosswalk. However, I understand the Census itself states that “to create the 2017 industry and 2018 occupation conversion rates, the bridgecode procedure used
data from 4 years of the ACS. Cases from the 2014 through 2017 1-year estimates files with a code that needed bridgecoding were double-coded from a list of appropriate codes.” (link:https://www.census.gov/content/dam/Census/library/publications/2020/demo/acs-tp78.pdf). Hence, there is much less space for confusion here, and I apologize for the extra trouble.

My apologies for the inconvenience and thanks in advance!

Best,
Pietro Valelongo

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As you have discovered, there are a number of different resources for examining occupations across years of the ACS that include a change in the occupation coding scheme.

  • Microdata files: The 2006-2010 5-year and 2008-2010 3-year ACS microdata files code respondents’ occupations based on the year data was collected. Records with MULTYEAR < 2010 are based on the 2000 SOC (which inform the 2000/2002 Census Occupation Codes) and those with MULTYEAR = 2010 are based on the 2010 SOC (which inform the 2010 Census Occupation Codes).
  • Summary files: The excerpt that you cite notes that for the creation of 2006-2010 summary tables that bridge this change, Census Bureau experts reassigned the occupations of each respondent interviewed in 2006-2009 to a new 2010 code. We provide these types of Census summary tables on our spatial data project website, IPUMS NHGIS.
  • Crosswalks: The Census Bureau produces a conversion rate crosswalk that allows researchers using the microdata to see the estimated percent of people in each old occupation code (e.g., 2000/2002 Census Occupation Codes) who would be assigned to each new code (e.g., the 2010 Census Occupation Codes). The comment in this IPUMS CPS guide to occupation code changes notes that this conversion rate crosswalk is available for comparing the 2008 and 2010 data in reference to analyses of the 2008-2010 3-year ACS microdata file. Note that I can no longer find this 3-year crosswalk on the Census Bureau’s website.

On a related note, it is unclear to me which years of data the conversion factors are based on; I was not able to find detailed documentation on this. I assume that the factors in the 3-year crosswalk to use data from 2008 and 2009 to calculate conversion factors for 2010 occupation codes. However, the Census Bureau also provides a document with conversion rates using the 2006-2010 5-year file on its Industry and Occupation Code Lists and Crosswalks page and the values in that document appear to be identical to those for the 3-year crosswalk. While I would expect the conversion rates to be similar overall, I would expect minor differences when using two additional years of data. You may want to reach out to the Census Bureau to determine the basis used for these values. Your interpretation of the note regarding the 2012-2018 crosswalk makes sense to me.

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