共查询到20条相似文献,搜索用时 31 毫秒
1.
Martin Peitz 《Economic Theory》1999,14(3):717-727
Summary. In models of product differentiation and location models it is implicitly assumed that consumers can afford to buy the differentiated
goods in the market. I show that with income heterogeneity there are severe existence problems of a price equilibrium in models
of horizontal product differentiation with unit demand because some consumers are income-constrained. The result generalizes
to other models of product differentiation, search, and switching costs. I present an alternative specification of variable
individual demand in which this kind of existence problem cannot arise.
Received: October 17, 1997; revised version: February 20, 1998 相似文献
2.
Summary. We prove that locally, Walras' law and homogeneity characterize the structure of market excess demand functions when financial
markets are incomplete and assets' returns are nominal. The method of proof is substantially different from all existing arguments
as the properties of individual demand are also different. We show that this result has important implications and is part
of a more general result that excess demand is an essentially arbitrary function not just of prices, but also of the exogenous
parameters of the economy as asset returns, preferences, and endowments. Thus locally the equilibrium manifold, relating equilibrium
prices to these parameters has also no structure.
Received: September 17, 1996; revised version: November 7, 1997 相似文献
3.
Summary. We present a consistent pure-exchange general equilibrium model where agents may not be able to foresee all possible future
contingencies. In this context, even with nominal assets and complete asset markets, an equilibrium may not exist without
appropriate assumptions. Specific examples are provided.
An existence result is proved under the main assumption that there are sufficiently many states that all the agents foresee.
An intrinsic feature of the model is bankruptcy, which agents may involuntarily experience in the unforeseen states.
Received: April 23, 1997; revised version: May 19, 1997 相似文献
4.
Harrison Cheng 《Economic Theory》2002,20(3):555-577
Summary. In an oligopoly game with cost uncertainty and risk averse firms, we show that Bertrand and Cournot equilibrium have different
convergence properties when the market is replicated. The Cournot equilibrium price converges to the competitive price. Under
very typical and somewhat general conditions, the highest Bertrand equilibrium price converges to one higher than the competitive
equilibrium. We also give examples to show how to compute the limit of the highest Bertrand equilibrium prices and illustrate
the ideas of the proof. We explore conditions under which the supply curve is upward sloping, a useful condition for our results.
Received: April 20, 2000; revised version: May 10, 2001 相似文献
5.
Luisa Fuster 《Economic Theory》1999,13(2):429-445
Summary. This paper studies the effects of uncertain lifetime on capital accumulation and growth and also the sensitivity of those
effects to the existence of a perfect annuities market. The model is an overlapping generations model with uncertain lifetimes.
The technology is convex and such that the marginal product of capital is bounded away from zero. A contribution of this paper
is to show that the existence of accidental bequests may lead the economy to an equilibrium that exhibits asymptotic growth,
which is impossible in an economy with a perfect annuities market or with certain lifetimes. This paper also shows that if
individuals face a positive probability of surviving in every period, they may be willing to save at any age. This effect
of uncertain lifetime on savings may also lead the economy to an equilibrium exhibiting asymptotic growth even if there exists
a perfect annuities market.
Received: April 17, 1996; revised version: December 9, 1997 相似文献
6.
Summary. General equilibrium models of oligopolistic competition give rise to relative prices only without determining the price level.
It is well known that the choice of a numéraire or, more generally, of a normalization rule converting relative prices into
absolute prices entails drastic consequences for the resulting set of Nash equilibria when firms are assumed to maximize profits.
This is due to the fact that changing the price normalization amounts to altering the objective functions of the firms. Clearly,
the objective of a firm must not be based on price normalization rules void of any economic content. In this paper we propose
a definition of the objective of a firm, called maximization of shareholders' real wealth, which takes shareholders' demand
explicitly into account. This objective depends on relative prices only. Real wealth maxima are shown to exist under certain
conditions. Moreover, we consider an oligopolistic market and prove the existence of a Nash equilibrium in which each firm
maximizes the real wealth of its shareholders.
Received: July 10, 1997; revised version: July 27, 1998 相似文献
7.
Summary. This paper establishes necessary conditions for demand complementarity to imply investment coordination failure and explores
the welfare implications of coordinated investment. Our main results caution against demand complementarities as a motive
for investment coordination. We find that: 1) generally, a strict notion of complementarity (Hicks) is necessary for the existence
of an investment coordination problem and 2) that when the problem does exist, coordination lowers social welfare without
countervailing sectoral asymmetries.
Received: June 19, 1996; revised version: December 5, 1997 相似文献
8.
Summary. We provide a “computable counterexample” to the Arrow-Debreu competitive equilibrium existence theorem [2]. In particular,
we find an exchange economy in which all components are (Turing) computable, but in which no competitive equilibrium is computable.
This result can be interpreted as an impossibility result in both computability-bounded rationality (cf. Binmore [5], Richter
and Wong [35]) and computational economics (cf. Scarf [39]). To prove the theorem, we establish a “computable counterexample”
to Brouwer's Fixed Point Theorem (similar to Orevkov [32]) and a computable analogue of a characterization of excess demand
functions (cf. Mas-Colell [26], Geanakoplos [16], Wong [50]).
Received: September 9, 1997; revised version: December 17, 1997 相似文献
9.
Boiteux's solution to the shifting-peak problem and the equilibrium price density in continuous time
Summary. Bewley's condition on production sets, imposed to ensure the existence of an equilibrium price density when is the commodity space, is weakened to allow applications to continuous-time problems, and especially to peak-load pricing
when the users' utility and production functions are Mackey continuous. A general form for production sets with the required
property is identified, and examples are given of technologies which meet the weakened but not the original condition: these
include industrial use and storage of cyclically priced goods. This gives a framework for settling Boiteux's conjecture on
the shifting-peak problem. To make clear the restriction implicit in Mackey continuity, we interpret it as interruptibility
of demand; and we point out that, without this assumption, the equilibrium can feature pointed peaks with singular, instantaneous
capacity charges. The general equilibrium results are supplemented by results for prices supporting individual consumer or
producer optima.
Received: February 16, 2000; revised version: July 7, 2001 相似文献
10.
Summary. This paper analyzes two equivalent equilibrium notions under asymmetric information: risk neutral rational expectations equilibria
(rn-REE), and common knowledge equilibria. We show that the set of fully informative rn-REE is a singleton, and we provide
necessary and sufficient conditions for the existence of partially informative rn-REE. In a companion paper (DeMarzo and Skiadas
(1996)) we show that equilibrium prices for the larger class of quasi-complete economies can be characterized as rn-REE. Examples
of quasi-complete economies include the type of economies for which demand aggregation in the sense of Gorman is possible
(with or without asymmetric information), the setting of the Milgrom and Stokey no-trade theorem, an economy giving rise to
the CAPM with asymmetric information but no normality assumptions, the simple exponential-normal model of Grossman (1976),
and a case of no aggregate endowment risk. In the common-knowledge context, we provide necessary and sufficient conditions
for a common knowledge posterior estimate, given common priors, to coincide with the full communication posterior estimate.
Received: May 29, 1997; revised version: July 18, 1997 相似文献
11.
传统的证明一般均衡存在性的方法都必须以连续的超额需求函数为条件。本文提供一种新方法突破这一局限。一般均衡分析中的个人择优问题是一个非线性规划问题,本文用动态规划方法来处理这一非线性规划问题,从而就克服了不连续超额需求函数带来的困难。运用这一新方法,本文证明了超额需求函数不连续时的存在性。 相似文献
12.
On the efficiency of markets for managers 总被引:1,自引:0,他引:1
Ján Zábojnik 《Economic Theory》2001,18(3):701-710
Summary. This paper examines the efficiency of the outside labor market in inducing optimal managerial behavior in the presence of
learning. It shows that the incentives provided by the market can be more efficient than the original analysis of Holmstr?m
[6] would suggest. Moreover, under a mild additional assumption, the existence of an -efficient equilibrium can be guaranteed if a manager is patient. This result supports Fama's [4] original idea that the outside
labor market can be efficient in disciplining top managers. These results also suggest that the empirically documented low
levels of explicit incentives for managers might be due to the presence of implicit incentives provided by the outside market.
Received: March 18, 1997; revised version: April 19, 2000 相似文献
13.
Jonathan L. Burke 《Economic Theory》1999,14(2):311-329
Summary. We combine and strengthen optimality and robustness theorems for the overlapping-generations model of money. Roughly, we
find a Pareto-optimal monetary equilibrium of a generic stationary economy that is near an optimal monetary equilibrium of
each nearby non-stationary economy. Since the nearby equilibria are monetary, the general problem of macroeconomic stabilization
reduces to maintaining the money supply. And since the nearby equilibria are optimal, stabilization is socially desirable.
Received: October 27, 1997; revised version: March 25, 1998 相似文献
14.
Ted To 《Economic Theory》1999,13(2):329-343
Summary. I examine a Knightian (1921) model of risk using a general equilibrium model of investment and trade. A population of agents
with various preference types can choose between a safe production technology and a risky production technology. In addition,
the distribution of types of agents changes through a standard evolutionary dynamic. For a given population distribution,
the equilibrium is in general inefficient, however, by allowing the population distribution to change in response to market
generated rewards, the population will converge to one where the equilibrium is efficient and where the population as a whole
behaves as if all agents were risk neutral.
Received: November 7, 1996; revised version: October 20, 1997 相似文献
15.
Daniel Trefler 《Economic Theory》1999,13(3):577-601
Summary. The Rubinstein and Wolinsky bargaining-in-markets framework is modified by the introduction of asymmetric information and
non-stationarity. Non-stationarity is introduced in the form of an arbitrary stochastic Markov process which captures the
dynamics of market entry and pairwise matching. A new technique is used for establishing existence and characterizing the
unique outcome of a non-stationary market equilibrium. The impact of market supply and demand on bilateral bargaining outcomes
and matching probabilities is explored. The results are useful for examining such questions as why coordination failures and
macroeconomic output fluctuations are correlated with real and monetary shocks.
Received: July 22, 1994; revised version: January 21, 1998 相似文献
16.
Endogenous technological change: a note on stability 总被引:1,自引:0,他引:1
Lutz G. Arnold 《Economic Theory》2000,16(1):219-226
Summary. This paper demonstrates that the steady-state solution of the optimal-growth problem in Romer's (1990) model of endogenous
technological change is globally saddle-point stable. Surprisingly, the proof of this result is trivial. Interest in the optimal
growth path is justified by the fact that there is a (unique) combination of production and R&D subsidies by means of which
the optimal growth path is attained as a market equilibrium.
Received: October 6, 1998; revised version: April 19, 1999 相似文献
17.
Kenneth J. Matheny 《Economic Theory》1998,11(2):379-402
Summary. To a greater extent than is often stressed in existing literature, preference assumptions affect responses to money shocks
in equilibrium monetary models. Temporary money shocks can have persistent real effects if the marginal utility of leisure
is a decreasing function of consumption, where leisure is measured as time endowment less market labor effort, and consumption
refers to market produced goods. This condition is an empirically supported implication of home production models. Though
not theoretically necessary for supporting the existence of short run real effects, the presence of distortionary taxes and
endogenous productivity can have significant quantitative effects on responses to temporary money supply shocks.
Received: August 21, 1996; revised version: February 3, 1997 相似文献
18.
Summary. This paper reports on the use of laboratory experimental techniques to create relatively complete economic systems. The creation
of these market systems reflects a first attempt to explore the nature of inherently interdependent environments and to assess
the ability of simultaneous equations equilibrium models like the classical static general competitive equilibrium model,
to predict aspects of system behaviors. In addition, the impact of the quantity of a fiat money was studied. The economies
were successfully created. Classical models capture much of what was observed.
Received: May 21, 1996; revised version: May 21, 1997 相似文献
19.
Leonidas C. Koutsougeras 《Economic Theory》1998,11(3):563-584
Summary. We introduce a new core concept, called the two-stage core, which is appropriate for economies with sequential trade. We
prove a general existence theorem and present two applications of the two-stage core: (i) In asset markets economies where
we extend our existence proof to the case of consumption sets with no lower bound, in order to capture the case of arbitrary
short sales of assets. Further, we show that the two-stage core is non empty in the Hart (1975) example where a rational expectations
equilibrium fails to exist. (ii) In differential information economies where we provide sufficient conditions for the incentive
compatibility of trades. Namely, that no coalition of agents can misreport the true state and provide improvements to all
its members, even by redistributing the benefits from misreporting.
Received: December 20, 1995; revised version: December 6, 1996 相似文献
20.
Even though pieces of empirical evidence individually may corroborate an economic theory, their joint existence may refute
that same theory. Testing of rational expectations models provides a concrete illustration of this principle. Surprisingly,
empirical refutation of a rational expectations model may occur without having to estimate that model, and the refutation
may be for a large class of expectations-based models and not just for a particular model specification. Narrow money demand
in the United Kingdom illustrates such refutation. The general proposition concerning corroboration and refutation strongly
favors the building of empirical models that are consistent with all available evidence.
First version received: July 1994/final version received: July 1997 相似文献