I agree. I believe that until the past century, the default behavior was to provide the majority of your family's needs yourself and only go outside of that for

I agree. I believe that until the past century, the default behavior was to provide the majority of your family's needs yourself and only go outside of that for a small portion where money would exchange hands. People lived on family farms where they grew their own food, made their own clothes, and built their own shelter. It is not clear in the article if barter was considered in past GDP numbers (e.g. "I'll trade you my cow for the wagon you built.") These days everyone works for cash and often pays for services that they could easily do themselves.