Stochastic Dominance, Pareto Optimality, and Equilibrium Asset Pricing

This paper introduces the concept of a factor subspace in competitive equilibrium asset pricing. A factor subspace contains the market portfolio and is such that every marketed contingent claim is second-order stochastically dominated by a claim from the factor subspace. Conditions are given for the existence of equilibrium, and it is shown how APT and CAPM can be interpreted in the framework of the paper. If sufficiently many call options on the market portfolio are traded, then the space spanned by these options can be used as the factor subspace.     

Nash Equilibrium and Welfare Optimality

If A is a set of social alternatives, a social choice rule (SCR) assigns a subset of A to each potential profile of individuals' preferences over A , where the subset is interpreted as the set of "welfare optima". A game form (or "mechanism") implements the social choice rule if, for any potential profile of preferences, (i) any welfare optimum can arise as a Nash equilibrium of the game form (implying, in particular, that a Nash equilibrium exists) and, (ii) all Nash equilibria are welfare optimal. The main result of this paper establishes that any SCR that satisfies two properties—monotonicity and no veto power—can be implemented by a game form if there are three or more individuals. The proof is constructive.     

Exhaustible Resources,Non-Convexity and Competitive Equilibrium

Theoretical underpinnings of competitive equilibrium in an exhaustible-resource market with non-convex (u-shaped) costs are proposed. The analysis extends to intertemporal production Novshek and Sonnenschein’s approximation of static competitive equilibrium by limits of Cournot equilibria. A problem with using Novshek and Sonnenschein’s method is that oligopolistic equilibrium, even an open-loop equilibrium, to which limits might be applied, does not exist when there is a non-convex technology. Using epsilon equilibrium as the equilibrium concept finesses this problem. There are two types of limiting competitive equilibrium. A third type of competitive equilibrium that has been prominent in the literature is found to be inconsistent with limiting approximations.     

人口红利与房地产收益率的无关性

本文通过建立一个跨期叠代(Overlapping Generation,OLG)模型,研究房地产均衡收益率和人口相关变量的关系,从理论上证明了在完全理性的市场中,房地产投资收益率与人口增长率无关,而与城市化水平负相关。采用中国房产价格以及人口数据,实证结果表明房地产收益率与人口变量关系不强,与城市化水平正相关,支持了上述结论。     

Competitive Equilibrium and Classroom Pit Markets

Efforts to show the relevance of economic concepts early in a student's education can prevent the “economics is not very useful” attitude from setting in. The author extends the work of Holt to describe a pit-market experiment used to illustrate the concept of competitive equilibrium. In addition to detailed instructions as to how to set up and conduct a pit-market experiment, the author discusses features of the data and provides accompanying materials, including software for the display of the data.     

The Optimality of Arbitrary Partial Equilibrium Welfare Analysis

This paper characterizes the general equilibrium foundation of arbitrary partial equilibrium welfare analysis in second‐best economies. While prior theory recognizes the importance of market distortions affected by relative price changes, it offers little guidance about the necessary scope of Marshallian partial equilibrium analysis. The paper determines necessary and sufficient conditions for optima of Marshallian total surplus functions to characterize second‐best Pareto‐optimal allocations. While these conditions confirm much of the traditional approach to applied welfare economics, they bring doubt about its reliability for public policy and concerns over its systematic use to build conventional economic wisdom.     

Stability and Turnpike Theorems in Dynamic Competitive Equilibrium

This study reviews the main results in the literature on the integration of competitive equilibrium theory and optimal growth theory, in particular those concerning the convergence of an equilibrium path to a stationary state (stability theorems).
JEL Classification Numbers: C6, D9.     

On the Optimality of the Competitive Process: Kimura's Theorem and Market Dynamics

This paper considers the optimality properties of a market economy in terms of three propositions that evaluate the outcomes of and the process of competition between a population of firms working within a given economic environment. We show that when firms differ in more than one competitive characteristic then competition does not select in general the most efficient firm nor does it always result in increases in the average efficiency with which resources are utilized. Drawing upon a theorem of Kimura, however, we show that competition has the property of maximizing the rate of change of the average selective characteristics in the population. We conclude that a more nuanced appraisal of the institutions of the competitive process is surely necessary. From an evolutionary standpoint, the outcomes of competition are always contingent on the nature of the selection environment and the characteristics of the whole population of firms that are being selected. This revised version was published online in July 2006 with corrections to the Cover Date.     

On the Optimality of Search Matching Equilibrium When Workers Are Risk Averse

This paper revisits the normative properties of search‐matching economies when homogeneous workers have concave utility functions and wages are bargained over. The optimal allocation of resources is characterized first when information is perfect and second when search effort is not observable. In the former case, employees should be unable to extract a rent. The optimal marginal tax rate is then 100%. As search effort becomes unobservable, an appropriate positive rent is needed and the optimal marginal tax rate is lower. Moreover, the pretax wage is lower in order to boost labor demand. Finally, in both cases, nonlinear income taxation is a key complement to unemployment insurance.     

Strategic Bargaining and Competitive Bidding in a Dynamic Market Equilibrium

This paper extends the bargaining and matching literature, such as Rubinstein and Wolinsky (1985), by considering a new matching process. We assume that a central information agency exists, such as real estate agencies in the housing market and employment agencies (or newspapers) in the labour market, which puts traders into direct contact with each other. With heterogeneity of trader preferences, equilibrium trade is characterized by existing traders on each side of the market trying to match with the flow of new traders on the other side (since existing traders have already sampled and rejected each other). Two procedures of trade co-exist, namely a strategic bilateral bargaining process and a competitive bidding process, depending on the number of potential matches a new trader obtains. We characterize the unique symmetric Markov perfect equilibrium to this stochastic trading game.     

Japanese Rice Market Liberalization: A Competitive Equilibrium Approach

This paper quantifies the effect of Japanese rice imports on the Japanese rice market with special attention to the farmland market in the year 2000, based on information available in 1997. Tariff and quota policies do not affect the equilibrium price of rice and rent significantly, given the current acreage controls. The removal of the acreage control programme would reduce the autarky price of rice by 30%. With free importation of rice into Japan, the price of rice would be halved, and the potential increase in the consumer surplus could be 0.3% of the 1995 Japanese GDP.
JEL Classification Numbers: F14, Q17, Q18.     

Competitive General Equilibrium with Finite Change and Theory of Policy Making

We visit the non‐equivalence of tariff and quota in higher dimensional finite change trade models when goods outnumber factors of production. Under competitive conditions, exogenous shocks (e.g., exposure to international trade) support the production of only a subset of commodities. If we try to protect some of the vanishing goods, tariff and quota will have different results when a tariff turns out to be a more restrictive policy than a quota, contrary to the conventional wisdom.     

The Theory of the Second Best and the Competitive Equilibrium Model

We study the international transmission of bank liquidity shocks from multinational, Islamic, bank-holding companies to their subsidiaries. Based on a total sample of 120 Islamic and conventional bank subsidiaries, we test whether foreign bank lending for Islamic and conventional banks is determined by different factors. We estimate a model that includes subsidiary and parent bank characteristics as well as host and home country variables. Our empirical findings show that lending is negatively affected by the fragility of conventional parent banks' subsidiaries. Nevertheless, we show that parent Islamic banks do not significantly affect lending by subsidiaries. Finally, we examine the market discipline regarding the transmission of liquidity shocks. We also find that reduction in foreign Islamic bank lending is stronger for those that are dependent on the interbank market. We establish that the depositors react to a deterioration of bank performance and punish their institutions by withdrawing their money. We show that market discipline has a more important role for Islamic banks, whereas liquidity needs determine the change in conventional banks.     

An appraisal of Piero Sraffa's 'The Laws of Returns under Competitive Conditions'

The paper proposes a new interpretation of Sraffa's 1926 Economic Journal article, ‘The Laws of Returns under Competitive Conditions’, according to which the latter derives from the same strategy of research which underlies its 1925 Italian precursor, ‘Sulle relazioni fra costo e quantità prodotta’. Sraffa tested the explanatory power of a Marshallian monopolistic partial equilibrium model and concluded that that model is able to treat one source of variable returns (firm-internal economies); but this articulation of Marshall‘s theory does not substantially improve on the trade-off between logical consistency and empirical relevance which afflicted the theory in its whole.     

Sustainability,Optimality, and Development Policy

Considering sustainability a matter of intergenerational welfare equity, this paper examines whether an optimal development path can also be sustainable. It argues that the general “zero‐net‐aggregate‐investment” condition for an optimal development path to be sustainable in the sense of the maximin criterion of intergenerational justice is too demanding to be practical, especially in the context of developing countries. It further argues that while the maximin criterion of sustainability may be appealing to the rich advanced industrial countries, for the poor developing countries it implies equalization of poverty across generations, and as such is too costly a moral obligation to be acceptable. The paper suggests that a compromise development policy that follows the optimal growth approach but adopts certain measures to mitigate both the intergenerational and intragenerational welfare inequalities may be more appropriate for these countries. Some of the principal elements of such a policy are highlighted.     

Aging,Factor Returns,and Immigration Policy

Immigration has various economic and non‐economic effects on the destination country's inhabitants. In this paper, we focus on the impact of immigration on factor returns and analyze how aging affects immigration policy, employing a dynamic political‐economy model of representative democracy. Aging, that is, a decline in the growth rate of the native population, has an expansionary effect on immigration in this framework. This immigration effect may even overcompensate the initial contraction of the labor force. We show that the immigration rate in the representative democracy equilibrium exceeds the immigration rate that would maximize welfare of current and future generations, and we also discuss the influence of social security on immigration policy.     

Price stabilizing, Pareto improving policies

One possible justification for a stabilization policy is that there is volatility in macro variables that individual agents cannot insure against. We study the simplest possible extension of the stochastic two-period, one agent and one commodity OLG model, where we have added one more period, with only one potential activity, namely, trading of contingent commodities. We assume, however, that markets are incomplete. In this case the Monetary equilibrium is not Pareto Optimal and for an open set of economies an allocation where fluctuations in realized savings are removed, Pareto dominates the monetary equilibrium. This allocation may be implemented by means of a monetary/fiscal policy. The policy considered has a simple rationale, namely that it removes some of the uncertainty that agents face by reducing price, i.e interest rate volatility. We consider two fundamental sources of such volatility, namely, respectively an objective and a subjective signal about the distribution of future endowments. The first case is when agents have rational expectations while the second case is studied in the context of agents having rational beliefs, beliefs which are consistent with empirical observations but not (necessarily) correct.