Murray N. Rothbard
Money in a Free Society
Yet, direct exchange of useful goods and services would barely suffice to keep an economy going above the primitive level. Such direct exchange--or barter--is hardly better than pure self-sufficiency. Why is this? For one thing, it is clear that very little production could be carried on. If Jones hires some laborers to build a house, with what will he pay them? With parts of the house, or with building materials they could not use? The two basic problems are "indivisibility" and "lack of coincidence of wants." Thus, if Smith has a plow, which he would like to exchange for several different things--say, eggs, bread, and a suit of clothes--how can he do so? How can he break up the plow and give part of it to a farmer and another part to a tailor? Even where the goods are divisible, it is generally impossible for two exchangers to find each other at the same time. If A has a supply of eggs for sale, and B has a pair of shoes, how can they get together if A wants a suit? And think of the plight of an economics teacher who has to find an egg-producer who wants to purchase a few economics lessons in return for his eggs! Clearly, any sort of civilized economy is impossible under direct exchange.