Venice’s elites were the chief beneficiaries. Like all open economies, theirs was turbulent. Today, we think of social mobility as a good thing. But if you are on top, mobility also means competition. In 1315, when the Venetian city-state was at the height of its economic powers, the upper class acted to lock in its privileges, putting a formal stop to social mobility with the publication of the Libro d’Oro, or Book of Gold, an official register of the nobility. If you weren’t on it, you couldn’t join the ruling oligarchy.