In an environment with private information, spatial separation, and limited communication, a currency-like object and more standard named credits can be distinguished. The credit objects can be used among agents in an enduring relationship, that is, among agents with known trading histories, whereas the currency-like object must be used among relative strangers. In this environment, collectively determined Pareto-optimal rules make the level of the currency-like object and the mix of currency to named credits responsive to individual needs and to economywide states. Total indebtedness is determined by the number of lenders, that is, by preference or demand shock, and the mix of currency to credits is determined by transaction patterns among the agents.

In the mid-1970s the International Whaling Commission concluded that the increased harvest by Alaskan Eskimos threatened the existence of the bowhead whale, which was slowly recovering from a period of open-access exploitation (1848-1914). This paper briefly discusses the economic history of the bowhead whale fishery in the western Arctic, simulates the population from 1848-1988, and presents a bioeconomic model that may be used to determine optimal Eskimo harvest for alternative rates of discount and weights on the bowhead population.

Though it is always mentioned first among the list of obvious manias, no serious effort has ever been expended to investigate the market fundamentals that might have driven the tulip speculation. This paper compiles time series on individual tulip prices and examines market fundamentals potentially driving prices. Most of the "tulipmania" was not obvious madness. High but rapidly depreciating prices for rare bulbs is a typical pattern in the flower bulb industry. Only the last month of the speculation, during which common bulb prices increased rapidly and crashed, remains as a potential bubble.

In the mid-1970s the International Whaling Commission concluded that the increased harvest by Alaskan Eskimos threatened the existence of the bowhead whale, which was slowly recovering from a period of open-access exploitation (1848-1914). This paper briefly discusses the economic history of the bowhead whale fishery in the western Arctic, simulates the population from 1848-1988, and presents a bioeconomic model that may be used to determine optimal Eskimo harvest for alternative rates of discount and weights on the bowhead population.

Though it is always mentioned first among the list of obvious manias, no serious effort has ever been expended to investigate the market fundamentals that might have driven the tulip speculation. This paper compiles time series on individual tulip prices and examines market fundamentals potentially driving prices. Most of the "tulipmania" was not obvious madness. High but rapidly depreciating prices for rare bulbs is a typical pattern in the flower bulb industry. Only the last month of the speculation, during which common bulb prices increased rapidly and crashed, remains as a potential bubble.

In an environment with private information, spatial separation, and limited communication, a currency-like object and more standard named credits can be distinguished. The credit objects can be used among agents in an enduring relationship, that is, among agents with known trading histories, whereas the currency-like object must be used among relative strangers. In this environment, collectively determined Pareto-optimal rules make the level of the currency-like object and the mix of currency to named credits responsive to individual needs and to economywide states. Total indebtedness is determined by the number of lenders, that is, by preference or demand shock, and the mix of currency to credits is determined by transaction patterns among the agents.

We develop a multicountry, dynamic general equilibrium model of product innovation and international trade to study the creation of comparative advantage through research and development and the evolution of world trade over time. In our model, firms must incur resource costs to introduce new products, and forward-looking potential producers conduct R & D and enter the product market whenever profit opportunities exist. Trade has both intraindustry and interindustry components, and the different incentives that face agents in different countries for investment and savings decisions give rise to intertemporal trade. We derive results on the dynamics of trade patterns and trade volume and on the temporal emergence of multinational corporations.

The authors develop a multicountry, dynamic general equilibrium model of product innovation and international trade to study the creation of comparative advantage through R$50D and the evolution of world trade over time. In their model, firms must incur resource costs to introduce new products, and forward-looking potential producers conduct R$50D and enter the product market whenever profit opportunities exist. Trade has both intraindustry and interindustry components, and the different incentives that face agents in different countries for investment and savings decisions give rise to intertemporal trade. The authors derive results on the dynamics of trade patterns and trade volume and on the temporal emergence of multinational corporations.

We examine an exchange economy with two agents: one risk neutral with a certain endowment and a second risk averse with a random endowment. The realization of the endowment is public but can be falsified by the second agent at a cost. For a broad class of falsification cost functions the optimal no-falsification contract is noncontingent on a left-hand interval and strictly increasing with a slope strictly less than one on a right-hand interval. Under a mild further restriction, optimal no-falsification contracts are, in addition, piece-wise linear. Optimal contracts may in general require falsifying the state, but for a set of the highest endowment realizations there is no falsification. We find simple conditions under which the optimal contract is a no-falsification contract. The model has applications that include financial, insurance, and employment contracts and tax policy.

A theoretical analysis of "optimal" (Nash equilibrium) tariff rates is presented. A numerical general equilibrium model is then used to find Nash equilibrium tariff rates for the United States and Canada. The Nash equilibrium tariffs are small relative to partial equilibrium estimates: 18 percent for the United States and 6 percent for Canada. The United States is essentially indifferent between the Nash equilibrium and free trade, while Canada is better off at the latter by $4 billion. Empirical results support theoretical predictions that the optimal tariff is smaller when the country is smaller, there are scale economies and free entry, and capital is internationally mobile.