Search Results
Working Paper
Debt constrained asset markets
We develop a theory of general equilibrium with endogenous debt limits in the form of individual rationality constraints similar to those in the dynamic consistency literature. If an agent defaults on a contract, he can be excluded from future contingent claims markets trading and can have his assets seized. He cannot be excluded from spot markets trading, however, and he has some private endowments that cannot be seized. All information is publicly held and common knowledge, and there is a complete set of contingent claims markets. Since there is complete information, an agent cannot enter ...
Report
Growth cycles and market crashes
Market booms are often followed by dramatic falls. To explain this requires an asymmetry in the underlying shocks. A straightforward model of technological progress generates asymmetries that are also the source of growth cycles. Assuming a representative consumer, we show that the stock market generally rises, punctuated by occasional dramatic falls. With high risk aversion, bad news causes dramatic increases in prices. Bad news does not correspond to a contraction of existing production possibilities, but to a slowdown in their rate of expansion. This economy provides a model of endogenous ...
Report
Bankruptcy and collateral in debt constrained markets
Typical models of bankruptcy and collateral rely on incomplete asset markets. In fact, bankruptcy and collateral add contingencies to asset markets. In some models, these contingencies can be used by consumers to achieve the same equilibrium allocations as in models with complete markets. In particular, the equilibrium allocation in the debt constrained model of Kehoe and Levine (2001) can be implemented in a model with bankruptcy and collateral. The equilibrium allocation is constrained efficient. Bankruptcy occurs when consumers receive low income shocks. The implementation of the debt ...
Working Paper
Evolving to the impatience trap: the example of the farmer-sheriff game
The literature on the evolution of impatience, focusing on one-person decision problems, finds that evolutionary forces favor the more patient individuals. This paper shows that in the context of a game, this is not necessarily the case. In particular, it offers a two- population example where evolutionary forces favor impatience in one group while favoring patience in the other. Moreover, not only evolution but also efficiency may prefer impatient individuals. In our example, it is efficient for one population to evolve impatience and for the other to develop patience. Yet, evolutionary ...
Report
Determinacy of equilibria in dynamic models with finitely many consumers
We consider a production economy with a finite number of heterogeneous, infinitely lived consumers. We show that, if the economy is smooth enough, equilibria are locally unique for almost all endowments. We do so by converting the infinite-dimensional fixed point problem stated in terms of prices and commodities into a finite-dimensional Negishi problem involving individual weights in a social value function. By adding artificial fixed factors to utility and production functions, we can write the equilibrium conditions equating spending and income for each consumer entirely in terms of ...
Journal Article
Failing to Provide Public Goods: Why the Afghan Army Did Not Fight
The theory of public goods is mainly about the difficulty in paying for them. Our question here is this: Why might public goods not be provided, even if funding is available? We use the Afghan Army as our case study. We explore this issue using a simple model of a public good that can be provided through collective action and peer pressure, by modeling the self-organization of a group (the Afghan Army) as a mechanism design problem. We consider two kinds of transfer subsidies from an external entity such as the U.S. government. One is a Pigouvian subsidy that simply pays the salaries, ...
Report
Monopoly and the incentive to innovate when adoption involves switchover disruptions
When considering the incentive of a monopolist to adopt an innovation, the textbook model assumes that it can instantaneously and seamlessly introduce the new technology. In fact, firms often face major problems in integrating new technologies. In some cases, firms have to (temporarily) produce at levels substantially below capacity upon adoption. We call such phenomena switchover disruptions, and present extensive evidence on them. If firms face switchover disruptions, then they may temporarily lose some unit sales upon adoption. If the firm loses unit sales, then a cost of adoption is the ...
Report
Rent-seeking and innovation
Innovations and their adoption are the keys to growth and development. Innovations are less socially useful, but more profitable for the innovator, when they are adopted slowly and the innovator remains a monopolist. For this reason, rent-seeking, both public and private, plays an important role in determining the social usefulness of innovations. This paper examines the political economy of intellectual property, analyzing the trade-off between private and public rent-seeking. While it is true in principle that public rent-seeking may be a substitute for private rent-seeking, it is not true ...
Report
The economics of ideas and intellectual property
Innovation and the adoption of new ideas are fundamental to economic progress. Here we examine the underlying economics of the market for ideas. From a positive perspective, we examine how such markets function with and without government intervention. From a normative perspective, we examine the pitfalls of existing institutions, and how they might be improved. We highlight recent research by ourselves and others challenging the notion that government awards of monopoly through patents and copyright are ?the way? to provide appropriate incentives for innovation.
Working Paper
Codes of conduct, private information, and repeated games
We examine self-referential games in which there is a chance of understanding an opponent?s intentions. Our main focus is on the interaction of two sources of information about opponents? play: direct observation of the opponent?s code-of-conduct, and indirect observation of the opponent?s play in a repeated setting.