Global instability in experimental general equilibrium: the Scarf example

Scarf (Int. Econ. Rev. 1 (1960) 157) proposed a model of dynamic adjustment in which the standard tatonnement price adjustment process orbits around, rather than converges to, the competitive equilibrium. Hirota (Int. Econ. Rev. 22 (1981) 461) characterized the price paths. We explore the predictions of Scarf's model in a non-tatonnement experimental double auction. The average transaction prices in each period do follow the path predicted by the Scarf and Hirota models. When the model predicts convergence the data converge; when the model predicts orbits, the data orbit in the direction predicted by the model. Moreover, we observe a weak tendency for prices within a period to follow the path predicted by the model.     

Tax schemes in a class of differential games

This paper evaluates tax schemes in a class of differential games. The results indicate that there are many tax schemes that support efficient resource usage, but each may fail to implement the targeted resource because of the multiplicity of equilibria. Since all of the equilibria are subgame perfect, it is difficult to predict which specific one arises. Care must then be taken in using a tax scheme as a remedy for the “tragedy of the commons.” The advantages of other policy instruments (including command-and-control regulation and a tradable permit system) are also discussed. I am indebted to Gerhard Sorger, Koji Shimomura, and two anonymous referees for their helpful comments. The detailed suggestions of one of the referees in particular have markedly improved the paper. Any remaining errors are mine. Partial financial support from MEXT KAKENHI(11730017, 18078004) is also gratefully acknowledged.     

The Walras core of an economy and its limit theorem

The Walras core of an economy is the set of allocations that are attainable for the consumers when their trades are constrained to be based on some agreed price system, such that no alternative price system exists for any sub-coalition that allows all members to trade to something better. As compared with the Edgeworth core, both coalitional improvements and being a candidate allocation for the Walras core become harder. The Walras core may even contain allocations that violate the usual Pareto efficiency. Nevertheless, the competitive allocations are the same under the two theories, and the equal-treatment Walras core allocations converge under general conditions to the competitive allocations in the process of replication.     

A Tradable Permit System in an Intertemporal Economy

It is known that in an intertemporal competitive economy, a tradable permit system may not achieve efficiency without setting appropriate permit interest rates (i.e., rewards for holding permits). To find the rates, however, we need to know in advance the path of efficient permit prices, which is difficult to obtain. This study intends to solve this problem in two ways. First, we analyze a special case in which the permit interest rates are given by a simple rule. For example, if the marginal abatement cost of pollution emission is constant, then the appropriate rate is to equal the monetary interest rate. As is the case for global warming, if the damage is caused in the future far beyond the planning period of the environmental program, the appropriate rate coincides with the marginal self-recovery of environmental stock under certain conditions. As a second approach, we propose a tradable permit system with a permit bank, as a mechanism by which the permit interest rates are generated endogenously without governmental intervention other than the issuance of permits. However, we also show that this approach raises the problem of indeterminacy of the equilibrium.     

Monotonicity and continuity of the critical capital stock in the Dechert–Nishimura model

We show that the critical capital stock of the Dechert and Nishimura (1983) model is a decreasing and continuous function of the discount factor. We also show that the critical capital stock merges with a nonzero steady state as the discount factor decreases to a certain boundary value, and that the critical capital stock converges to the minimum sustainable capital stock as the discount factor increases to another boundary value.     

Feasibility and optimality of sustainable growth under materials balance

Pollution from consumption and production is an inevitable part of economic processes. We employ a materials balance approach and develop an endogenous growth theory, with recycling activity, to examine the evolution of the economic and environment systems. This paper provides feasibility and optimality conditions for sustainable economic growth with rising environmental quality. The fundamental condition of feasibility is that the flow of natural resources, which eventually returns to the environment as waste and pollution, has a negative growth rate in the long run.     

An International Portfolio Optimization Model Hedged with Forward Currency Contracts

We will propose a new method for constructing an optimal portfolio in which the fund is allocated to assets and currencies of several countries. Traditionally, two or three stage method is adopted in this field. However, it neglects the risk associated with variations of the rate of return of individual assets and the exchange rate of currencies. Instead, the new method enables one to simultaneously determine the optimal amount of fund to be allocated to each asset and the amount of the forward contracts on currencies. The resulting optimization problem is apparently a nonconvex minimization problem due to the existence of product terms in the objective function. We will show, however, that a globally optimal solution can be calculated by a standard algorithm in an efficient way. Also we will demonstrate that the new method leads to a substantially better result using historical data of U.S., Japan and Germany.     

Platforms and Real Options in Industrial Organization

We need a robust theory to analyse the dynamics of new industrial organizations that are being created by the explosion of information technology. This paper sets out a new theoretical perspective and suggests a new empirical framework towards formulating such a theory. The new conceptual tools of analysis presented here include the "platform" as a key element of new market structures, "real options" analysis to deal with genuine uncertainty, and an understanding of a new form of competition that takes place among different platforms.
JEL Classification Numbers: L10, L12, L15, D81.     

质量功能展开方法的研究与应用（节选）——质量功能展开和知识管理

9月25～26日第14届国际质量功能展开研讨会在北京召开.这次会议是由国际质量功能展开组织委员与中国质量协会共同举办的.质量功能展开(Quality Function Deployment,简称QFD)于上世纪70年代诞生于日本,80年代在欧美等工业发达国家得以不断发展和完善.QFD是近年来在国际上非常流行的质量管理技术和方法.