INSUFFICIENT ENTRY OF EMPLOYEE‐CONTROLLED FIRMS IN A FREE‐ENTRY OLIGOPOLY

This study is a theoretical examination of whether employee‐controlled firms (ECFs) enter a free‐entry oligopolistic market excessively or insufficiently, from the viewpoint of welfare maximization. The excess entry theorem is well known in oligopoly theory. According to this theorem, a greater number of profit‐maximizing firms enter a free‐entry oligopolistic market than is optimal for welfare maximization. We demonstrate the possibility that insufficient entry arises when ECFs compete in a free‐entry market. In particular, we show that if both the demand and cost functions are convex, insufficient ECF entry necessarily occurs. Our results suggest that competition among firms seeking purposes other than profit might lead to insufficient entry because differences in competing firms’ objectives affect the intensity of market competition.     

When Do Export Subsidies Have a Redistributional Role?

If an export subsidy is efficient, that is, has a surplus-transfer role, then there exists an implicit function relating the optimal level of the subsidy to the income target in the agricultural sector. If an export subsidy is inefficient no such function exists. We show that dependence exists in large-export equilibrium, not in small-export equilibrium and show that these results remain robust to concerns about domestic tax distortions. The failure of previous work to produce this result stems from its neglect of the income constraint on producer surplus in the programming problem transferring surplus from consumers and taxpayers to farmers.     

Coase on broadcasting, advertising and policy

The initial argument developed in this paper is that a wants-basedconception of the objectives of policy, clearly operative inhis broadcasting studies, together with the acceptance of certainassumed properties of the competitive process, tightly constrainCoase's work. At times, for example, when considering the impactof advertising, Coase accepts that the assessment of policymust be carried out on a broader basis. Coase does not, however,go on to develop a criterion beyond wants. Elsewhere, he highlightsthe importance of the distinction between wants and needs. Thispaper further argues that, by elaborating upon this distinction,it becomes possible to give an indication of how a broader frameworkfor the assessment of policy might be developed.     

Preference profiles sustaining Arrow's theorem

Summary. Arrow's theorem is proved on a domain consisting of two types of preference profiles. Those in the first type are “almost unanimous": for every profile some alternative x is such that the preferences of any two individuals merely differ in the ranking of x, which is in one of the first three positions. Profiles of the second type are “appropriately heterogeneous”, with preferences similar to those generating the “paradox of voting”. Received: March 9, 2000; revised version: June 7, 2001     

Arbitrage Opportunities in Diverse Markets via a Non-equivalent Measure Change

We study arbitrage opportunities in diverse markets as introduced by Fernholz (J Math Econ 31:393–417, 1999). By a change of measure technique we are able to generate a variety of diverse markets. The construction is based on an absolutely continuous but non-equivalent measure change which implies the existence of instantaneous arbitrage opportunities in diverse markets. For this technique to work, we single out a crucial non-degeneracy condition. Moreover, we discuss the dynamics of the price process under the new measure as well as further applications.Both authors gratefully acknowledge financial support by the National Centre of Competence in Research “Financial Valuation and Risk Management” (NCCR FINRISK). The NCCR FINRISK is a research program supported by the Swiss National Science Foundation. The first author also thanks Credit Suisse Group for financial support.     

Hazard rate for credit risk and hedging defaultable contingent claims

We provide a concise exposition of theoretical results that appear in modeling default time as a random time, we study in details the invariance martingale property and we establish a representation theorem which leads, in a complete market setting, to the hedging portfolio of a vulnerable claim. Our main result is that, to hedge a defaultable claim one has to invest the value of this contingent claim in the defaultable zero-coupon.Received: April 2003Mathematics Subject Classification: 91B24, 91B29, 60G46JEL Classification: G10The authors would like to thank D. Becherer and J.N. Hugonnier for interesting discussions and the anonymous referee whose pertinent questions on the first version of this paper help them to clarify the proofs. All remaining errors are ours.     

A general-equilibrium re-appraisal of the Stolper-Samuelson theorem

This paper conducts a general-equilibrium analysis of the Heckscher-Ohlin model in which product price is endogenized. It applies both marginal and infra-marginal comparative-static analyses to examine the co-movement of factor and product prices. It shows that the Stolper-Samuelson theorem's prediction does not always hold, in particular, it does not always hold inside the diversification cone when changes in production parameters lead to changes in prices; or when the general equilibrium jumps from one structure to another. The result of this paper supports the everything-possible theorem and casts doubt on the general applicability of other core trade theorems derived from the same framework as the Stolper-Samuelson theorem.     

S-S定理在中国的适用性检验——贸易对地区和城乡收入差别的影响

1941年根据发达国家情况提出的S-S定理在中国是不是适用,需要检验.根据中国这个发展中大国各地经济贸易发展程度不同和城乡差别巨大这样两个事实,对贸易与反映中国整体收入分配情况的基尼系敖、贸易与中国地区收入差距、贸易与中国城乡收入差别之间的关系,分别进行实证检验后发现,被解释的三大收入分配关系的确发生了如S-S定理所说的变化.因此.这个定理在中国是适用的.     

解读福利经济学

福利经济学是西方经济学的一个重要理论分支。对福利经济学的核心概念、基本理论加以梳理 ,并对福利经济学的发展趋势进行了探讨。     

外部性、负外部性及其在生态保护中的应用

外部性是社会生活生产中很常见的一种经济现象,由于行为和结果的不一致造成的负外部性更是普遍,负外部性一般的解决办法为庇古税和科斯定理。以国内影视剧组破坏环境为例,分析负外部性在生态保护中的应用,提出通过科斯手段、庇古税、法律手段、媒体社会力量等多种方法解决外部性问题。