Regarding: Does CLASSWKR in ASEC before 1988 include incorporated and non-incorporated self-employment?

Based on the frequency distribution of CLASSWKR (using the IPUMS online data analysis system), there is a discrete jump in 1988 in the percentage of self-employed individuals when the CLASSWKR variable started breaking self-employment into incorporated and non-incorporated (see below image). Any insights on this? This is the discrepancy we are running into for our research.

Below is a quote from the BLS publication, “Self-employment in the United States” March 2016, Hipple and Hammond.

“Since the late 1940s, data on self-employment have been collected regularly as part of the Current Population Survey (CPS), a monthly sample survey of about 60,000 households that provides employment and unemployment data for the nation’s civilian non-institutional population ages 16 and older. Since 1967, the official BLS estimates of self-employment have included only the unincorporated self-employed. Although it is possible to identify the incorporated self-employed separately, they are counted as wage and salary workers in the official statistics because, legally, they are employees of their own business.”

Overall, it appears the detailed class of worker data is available. If the CLASSWKR code 10 only includes non-incorporated businesses and we cannot get the detailed breakdown before 1988 from IPUMS, is it possible to get the data directly from the BLS?

There were significant changes between the 1987 and 1988 ASEC, so it is hard to pinpoint exactly what may be causing this jump. You can read about the changes in 1988 here (in the Historical File Information section; page 1-2).

It does appear that the 1987 ASEC did ask the question about class of worker with options for self-employment broken into incorporated and non-incorporated (see page 112 of the document linked, question 23E), however, the source data we have does not have this separation. You can try contacting the BLS to see if they have the information.

The quote you reference may also be related to the availability of CLASSWLY, which specifies the class of worker last year, and has self-employment broken down into incorporate and non-incorporated categories back to 1976.