Cambridge University reports on research by economic historian Sheilagh Ogilvie. In some communities in Germany, people recorded their possessions at the time of marriage. This can allow Ogilvie to reconstruct the development of the German economy from 1600 to 1900

“Aspirations for the latest fashions, furnishings and stimulants motivated people to shift time from leisure and do-it-yourself to income-earning work, creating a virtuous circle,” explained Professor Ogilvie. “More work meant more earnings, more earnings meant people could buy more consumer goods, and this spurred producers to innovate and expand.”

Glen Whitman, who emailed the link to me, knew that I would be struck by the shift from non-market activities to market work. That is what happens when people create patterns of sustainable specialization and trade (PSST). It goes into reverse when patterns break down, until new patterns are created.