Does CLASSWKR in ASEC regarding self-employment (code 10) include incorporated and non-incorporated before 1988?

The CLASSWKR variable in ASEC breaks self-employment into non-incorporated and incorporated beginning in 1988 (codes 13 and 14). However, there is only one category (self-employed code 10) before 1988. Does this broad category include both incorporated and non-incorporated self-employed individuals? In addition, the CLASSWKLY variable (class of worker last year) in ASEC breaks self-employment into incorporated and non-incorporated all the way back to 1976. Would it be possible to obtain these breakdowns for CLASSWKR beginning in 1976?

Yes, in years prior to 1988 all types of self-employed people are combined into the one category ==10 “self-employed”. IPUMS CPS is only able to provide data as collected and provided by the US Census Bureau. In years prior to 1988 the detail available in CLASSWLY is unfortunately not available in CLASSWKR.