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?