I am conducting a study of occupations over time (1980-2012). Did OCC1990, IND1900 change over time>

#1

I am conducting a study of occupations over time (1980-2012). Did OCC1990, IND1900 change over time?

I am finding a major drop in my numbers for the RETAIL and DOMESTIC occupations in 2010.

#2

While the OCC1990and IND1990 are consistently coded for comparability overtime, the source variables (OCCand IND), upon which OCC1990 and IND1990 are based, change about every 10 years. The 2010 ACS marked the first year the Census Bureau used the SOC 2010 coding scheme to generate the ACS occupation codes, so it is possible that the differences you are seeing are related to a coding change. These changes include the elimination and addition of codes as well as aggregation of codes to maintain confidentiality. IPUMS-USA uses the crosswalks provided by the Census Bureau to create the harmonized OCC1990 and IND1990 variables. This process is described in greater detail on the IPUMS-USA Occupation and Industry page. This page includes links to crosswalks showing the relationship between OCC and OCC1990 as well as IND and IND1990.

I hope this helps