Monkeys aren't people, and the exchanges in the monkey "economy" are at best at analogy for a human economy. As with all analogies, there are positive parallels as well as disanalogies. The issue originally raised was whether the monkeys engaged in barter or monetary exchange. That, of course, depends on what the essential characteristics of barter or monetary exchange are taken to be. It won't do, however, to define the terms in such a way that historical periods in which exchange was largely conducted in gold and silver coin or fully backed paper are categorized as barter. For that purpose, it is the lack of exchangeability by right (ultimately through some shorter or longer chain) into something with intrinsic value that is the most salient feature of money. I take the monkey's tokens to fit that characteristic. I agree with Matt Forstater that human monetary systems typically involve infinite regress valuation. This may be a disanalogy with the monkey economy, but it does not seem to me to address the salient feature in his original argument. Also, the fact that I value money because I believe that you value money, does not imply that the money that I hold is your liability. Chains of valuation of financial assets must be anchored in real goods -- sometimes they end in pork bellies; sometimes they end in dollars. In our society, dollars are real goods -- despite the fiction that they are liabilities of the Federal Reserve -- because they ultimately supply a real service: as Matt notes, they get the IRS off your back. But notice that this is not because they are a liability that must be accepted by the issuer -- the IRS is not the issuer. Anchoring the value of dollars in the payment of taxes is a sufficient but not necessary condition of its value. For example, when the Australians wanted to monetize exchange among tribesmen in New Guinea, they proceeded in two steps. First, they conditioned the tribesmen to valuing externally produced goods, such as metal pots and knives, by giving them away. Then they offered those same goods only in exchange for paper currency. The natives had to obtain the paper currency by working in order to purchase the goods. No taxes are involved. Nor do the exchanges at Australian stores involve a right implied by the "liability" nature of the currency: after all, the prices of the goods could change; certain goods may or may not be offered. All that is needed is that the natives have a belief that the currency would frequently enough serve as a means to obtaining the goods. As I have described it, the situation in New Guinea is rather closely analogous to that of the monkeys. Yet, it may seem to fall short of a full bodied monetary economy if the exchanges were always short circuits from Australian employers to native workers and back to Australian shops. But if the natives begin to use the currency in longer circuits amongst themselves, then a full bodied monetary economy would be in place. The monkeys apparently were not given the opportunity to develop such exchanges amongst themselves. But like all laboratory experiments, the point was to examine some feature of reality by isolating it from others. So, while there are positive analogies, there are also intentional disanalogies. Kevin Hoover