Volume 1, Issue 2

This paper studies a growth model that is able to match several key facts of economic history. For thousands of years, the average standard of living seems to have risen very little, despite increases in the level of technology and large increases in the level of the population. Then, after thousands of years of little change, the level of per capita consumption increased dramatically in less than two centuries. Quantitative analysis of the model highlights two factors central to understanding this history. The first is a virtuous circle: more people produce more ideas, which in turn makes additional population growth possible. The second is an improvement in institutions that promote innovation, such as property rights: the simulated economy indicates that arguably the single most important factor in the transition to modern growth has been the increase in the fraction of output paid to compensate inventors for the fruits of their labor.

Many argue that the intrinsic uselessness of fiat money makes ``coordination'' an essential part of monetary theory: consumers could all equally well coordinate on believing that fiat money has no value. The coordination view suggests, however, that many transactions patterns are in fact possible as economic outcomes. Indeed, we do seem to observe different patterns of exchange at different times and in different places, and the relative importance of money is probably not a universal constant. The main goal of this paper is to develop a simple model of money's role as a medium of exchange when multiple transaction patterns are possible. The coordination view is conveniently analyzed in a dynamic version of Shubik's game-theoretic trading post economy. This economy allows a role for fiat money, and fiat money can coexist with barter in exchange. There are multiple decentralized equilibria, and one of these coincides with the equilibrium of a cash-in-advance economy: the model can be viewed as a generalization of the cash-in-advance framework. Other equilibria use both money and other, intrinsically valuable, objects as media of exchange. One implication of the coordination view is that the effects of monetary policy in general depend on the equilibrium transactions pattern. The paper illustrates this point by showing how estimates of the welfare costs of inflation may be biased depending on the econometrician's beliefs about the transactions patterns.

In a dynamically efficient economy, can a government roll its debt forever and avoid the need to raise taxes? In a series of examples of economies with zero growth, this paper shows that such Ponzi games may be infeasible even when the average rate of return on bonds is negative, and may be feasible even when the average rate of return on bonds is positive. The paper then reveals the structure which underlies these examples.