The Economic Way of Thinking 13th Edition by David Prychitko, Peter Boettke, Paul Heyne

Exercise 2

For almost 2000 years, people on the Island of Yap in Micronesia have used circular stones as money, though more recently they are more of a symbol than a general medium of exchange. Various people own portions of the stones.
(a) Because the stones are worthless when broken and also heavy, People leave the larger ones where they are and simply take note of the fact that ownership has changed. How is this similar to paying by check?
(b) Some of the stones are propped up in rows in village "banks." Suppose that the person who lives next door to the "bank" is entrusted with the responsibility of keeping track of who owns what portion of each stone. How could this person use his position to make loans and thereby expand the quantity of money in Yap?