NP

The 1910 and 1920 censuses sorted workers as employers, wage earners or working on their own account. In 1930 the class of worker column added a fourth code, NP, for a relative of the head who worked regularly without wages on the family farm or in the family shop or store. Housework and small chores did not count.

The 1930 instructions give a son working on his father's farm and a wife working in her husband's store as examples. The 1940 and 1950 instructions keep NP with the same meaning, so an NP entry tells you the family ran its own farm or business.