This paper shows that a monopolistically competitive economy with real investment can have multiple rational expectations equilibria: one is associated with entrepreneurs' optimistic expectations about future demand; another with entrepreneurs' pessimism. It also shows that an optimistic expectational equilibrium Pareto dominates a pessimistic equilibrium. An investment subsidy can be beneficial both by reducing the original underinvestment distortion and by changing firms' expectations from pessimistic to optimistic. The most important assumption is increasing returns to scale, and monopolistic competition makes increasing returns consistent with each producer's optimization.

We develop an infinite horizon macroeconomic model of banking that allows for liquidity mismatch and bank runs. Whether a bank run equilibrium exists depends on bank balance sheets and an endogenous liquidation price for bank assets. While in normal times a bank run equilibrium may not exist, the possibility can arise in recessions. A run leads to a significant contraction in intermediation and aggregate economic activity. Anticipations of a run have harmful effects on the economy even if the run does not occur. We illustrate how the model can shed light on some key aspects of the recent financial crisis.

Japan has been in a slump for the past decade. After GDP had been growing by on average 4 percent during the 1980’s, the growth rate dropped to 1 percent in the 1990’s. Asset prices also fluctuated significantly: capital gains on stocks and real estate in the 1980’s, followed by capital losses in the 1990’s, were both on the order of a few years’ worth of GDP, even after taking inflation into account. Together with production and asset prices, the fraction of nonperforming loans fluctuated substantially. These are by no means all bank loans. For the nonfinancial corporate sector in Japan, the ratio of financial assets to total assets is about 40 percent, much higher than in the United States. Such financial assets include loans to and securities of other private agents. That is, nonfinancial institutions simultaneously borrow from and lend to each other on a significant scale. Many nonperforming loans are interlocked, paralyzing the financial system. It is important to recognize that these swings have been experienced by almost all sectors of the Japanese economy. Yet in other countries, comparable movements in asset prices have had less widespread consequences. For example, the recent fluctuations in the NASDAQ index in the United States have been no smaller than those of asset prices in Japan, but the damage appears to be contained to closely related sectors. Although U.S. equity-holders, particularly pension funds, have lost value, the level of nonperforming loans is relatively limited up to now. The question is: Why does there appear to be more contagion in some countries than in others? Has contagion anything to do with the nature of financing or the extent to which there are inter-locking loans? In this theoretical paper, we examine two different mechanisms by which contagion may occur. In both cases, propagation is through balancesheet effects. First, through the indirect effects that fluctuations in asset prices have on collateral values. Second, through the direct effects that default on or postponement of debt repayments have when there are chains of credit.

Plenary talk delivered at the annual meeting of the Society for Economic Dynamics.(This abstract was borrowed from another version of this item.)

The essential function of money is its role as a medium of exchange. We formalize this idea using a search-theoretic equilibrium model of the exchange process that captures the "double coincidence of wants problem" with pure barter. One advantage of the framework described here is that it is very tractable. We also show that the model can be used to address some substantive issues in monetary economics, including the potential welfare-enhancing role of money, the interaction between specialization and monetary exchange, and the possibility of equilibria with multiple fiat currencies.

The paper presents a model of a monetary economy where there are differences in liquidity across assets. Money circulates because it is more liquid than other assets, not because it has any special function.

The authors construct a model of a dynamic economy in which lenders cannot force borrowers to repay their debts unless the debts are secured. In such an economy, durable assets play a dual role: not only are they factors of production but they also serve as collateral for loans. The dynamic interaction between credit limits and asset prices turns out to be a powerful transmission mechanism by which the effects of shocks persist, amplify, and spill over to other sectors. The authors show that small, temporary shocks to technology or income distribution can generate large, persistent fluctuations in output and asset prices.

We analyze economies in which individuals specialize in consumption and production and meet randomly over time in a way that implies that trade must be bilateral and quid pro quo. Nash equilibria in trading strategies are characterized. Certain goods emerge endogenously as media of exchange, or commodity money, depending both on their intrinsic properties and on extrinsic beliefs. There are also equilibria with genuine fiat currency circulating as the general medium of exchange. We find that equilibria are not generally Pareto optimal and that introducing fiat currency into a commodity money economy may unambiguously improve welfare. Velocity, acceptability, and liquidity are discussed.

How important is monopolistic competition to an understanding of the effects of aggregate demand on output? We ask the question at three levels. Can monopolistic competition, by itself, explain why aggregate demand movements affect output? Can it, together with other imperfections, generate effects of aggregate demand in a way that perfect competition cannot? If so, can it give an accurate account of the response of the economy to aggregate demand movements? The answers are no, yes, and yes.

This article incorporates banks and banking panics within a conventional macroeconomic framework to analyse the dynamics of a financial crisis of the kind recently experienced. We are particularly interested in characterizing the sudden and discrete nature of banking panics as well as the circumstances that make an economy vulnerable to such panics in some instances but not in others. Having a conventional macroeconomic model allows us to study the channels by which the crisis affects real activity both qualitatively and quantitatively. In addition to modelling the financial collapse, we also introduce a belief driven credit boom that increases the susceptibility of the economy to a disruptive banking panic.