Impersonal exchange is the hallmark of an advanced society and money is one key institution that supports it. Economic theory regards money as a crude arrangement for monitoring counterparts’ past conduct. If so, then a public record of past actions—or memory—should supersede the function performed by money. This intriguing theoretical postulate remains untested. In an experiment, we show that the suggested functional equivalence between money and memory does not translate into an empirical equivalence: money removed the incentives to free ride, while memory did not. Monetary systems performed a richer set of functions than just revealing past behavior. Keywords: Cooperation, intertemporal trade,experiments, institutions, social norms.