“The great affair, we always find, is to get money.” So wrote Adam Smith, but he might have been surprised to visit the Micronesian island of Yap, where a coin’s value is determined by its size. If a native pays you a large debt, you might find yourself with a limestone coin 12 feet in diameter and weighing several tons. You might display it outside your home, as a status symbol — or you might just leave it where it is (even underwater) and agree that ownership has been transferred. Easier on the back.