Can anyone help me understand how ERSCOR50 is derived for pre-1950 years?

In the 1850 Census data file the ERSCOR50 var is populated, yet there is no income data in that year. Documentation indicates that this variable was “assigned” but I am not clear how that was done. Thanks

The construction of ERSCOR50 relies on different income variables in different years. In 1950 specifically, the calculations rely on INCWAGE and INCBUSFM, which are both available in 1950. More details about the construction of ERSCOR50 can be found on the variable description tab.