To The Raider Goes The Surplus? A Reexaminationof the Free-Rider Problem

This paper reexamines Grossman and Hart's (1980) insight into how the free-rider problem excludes an external raider from capturing the increase in value it brings to R firm The inability of the raider to capture any of the surplus depends critically on the assumption of equal and indivisible shareholdings–the one-share-per-shareholder model In contrast, we show that once shareholdings are large and potentially unequal, a raider may capture a significant part of the increase in value Specifically, the free-rider problem does not prevent the takeover process when shareholdings are divisible.     

Equilibria in a class of aggregative location games

Consider a multimarket oligopoly, where firms have a single license that allows them to supply exactly one market out of a given set of markets. How does the restriction to supply only one market influence the existence of equilibria in the game? To answer this question, we study a general class of aggregative location games where a strategy of a player is to choose simultaneously both a location out of a finite set and a non-negative quantity out of a compact interval. The utility of each player is assumed to depend solely on the chosen location, the chosen quantity, and the aggregated quantity of all other players on the chosen location. We show that each game in this class possesses a pure Nash equilibrium whenever the players’ utility functions satisfy the assumptions negative externality, decreasing marginal utility, continuity, and Location–Symmetry. We also provide examples exhibiting that, if one of the assumptions is violated, a pure Nash equilibrium may fail to exist.     

Gross substitutability of point-to-set correspondences

In this paper the notion of gross substitutability for the multi-valued case is studied. It is proved that, if in a pure exchange equilibrium model gross substitutability and some auxiliary conditions prevail, then (a) the set of equilibria is a Cartesian product of a convex set of equilibrium resource allocations and a convex cone of equilibrium prices; hence all equilibria are equiadvantageous for every trader; (b) the weak axiom of revealed preference holds in any equilibrium; (c) any equilibrium is stable with respect to reallocations of initial resources. Some situations in which Walras' law does not hold are considered as well.     

A NEW CINDERELLA STORY: JOINT VENTURES AND THE PROPERTY RIGHTS THEORY OF THE FIRM

Joint ventures (JVs) are a common form of inter-firm collaboration and, unsurprisingly, the subject of a vast literature, extending from economics to management and business studies. Issues of control are central to the definition of JVs, and this naturally calls for an interpretation in the context of the property rights theory (PRT) of the firm. In a series of seminal papers, Grossman, Hart and Moore (GHM) offer a rigorous framework to predict the allocation of control rights. Notably, under the standard assumptions of GHM, JVs are suboptimal. However, JVs are not suboptimal in more general settings where a number of the original framework's assumptions are relaxed. In the context of PRT, this paper surveys more than 20 contributions that address the optimality of JVs under contract incompleteness. The surveyed papers question the assumptions of GHM and reveal the circumstances in which JVs outperform sole ownership. Although contributions are scattered over time and bibliographical sources, we believe sufficient material has accumulated over 25 years of economic modelling to encourage some systematization. The discussion is organized in an intuitive and non-technical way; in particular, effort is devoted to analysing each paper in detail and providing a unified framework.     

Pure and randomized equilibria in the stochastic von Neumann–Gale model

The paper examines the problem of the existence of equilibrium for the stochastic analogue of the von Neumann–Gale model of economic growth. The mathematical framework of the model is a theory of set-valued random dynamical systems defined by positive stochastic operators with certain properties of convexity and homogeneity. Existence theorems for equilibria in such systems may be regarded as generalizations of the Perron–Frobenius theorem on eigenvalues and eigenvectors of positive matrices. The known results of this kind are obtained under rather restrictive assumptions. We show that these assumptions can be substantially relaxed if one allows for randomization. The main result of the paper is an existence theorem for randomized equilibria. Some special cases (models defined by positive matrices) are considered in which the existence of pure equilibria can be established.     

The set of equilibria of first-price auctions

I specify the class of functions that are equilibria of symmetric first-price auctions. A formula to recover the distribution of valuations for any equilibrium bidding strategy is given.     

Corporate investment,dividend decisions,differential taxation and the no-arbitrage condition

Masulis and Trueman (1988) investigated corporate investment and dividend decisions under differential personal taxation. They assumed investors in different tax brackets, a state-preference complete market (which includes pure securities for each state) with a ban on short-selling. They concluded that shareholders prefer non-zero dividend payment. In their model, the restrictions on short-sales were needed to bound tax arbitrage profits, among investors in different tax brackets, so that equilibrium could be reached. However, the joint assumptions of complete markets, and restrictions on short-selling, are inconsistent. By utilizing more recent results, from the tax arbitrage literature, we allow short-selling, and examine the role and implications of the no-arbitrage condition. We show that, with investors in different tax brackets, equilibrium is feasible. We conclude that a revised Masulis and Trueman type model does not explain a non-zero optimal dividend policy.     

Equilibria,stability and asymptotic dominance in a speculative market with heterogeneous traders

We consider a pure exchange economy where one risky and one riskless security are traded in discrete time. Individual demands are expressed as fractions of individual wealth and depend on traders’ forecasts about future price movement.Introducing the ‘Equilibrium Market Line’ as the locus of all possible equilibrium returns, we show that, irrespectively of the number of traders and of their investment behavior, the economy possesses isolated equilibria where a single agent dominates the market and continuous manifolds of equilibria where many agents hold finite wealth shares. Moreover, we prove that no global dominance order relation among strategies can be defined.     

Corporate takeovers,stockholder returns and executive rewards

Various motives for making corporate acquisitions have been forwarded in the managerial economics literature. Two that have received a lot of attention are the maximization of stockholder wealth and the maximization of senior management's utility. These two alternative views can lead to different acquisition decisions. The paper examines the returns to senior management and the returns to stockholders following corporate takeovers in the United Kingdom. The evidence suggests that if shareholders profit from takeovers then so do the senior' management. Of more interest, however, is the finding that if acquisitions result in a reduction in stock market value for the acquiring firm, their senior management appear to gain. In particular, senior management remuneration increases substantially after an acquisition. This evidence is consistent with the maximization of senior management's utility being an important motive in many corporate-acquisition decisions.     

Contests with investment

Perfectly discriminating contests (all pay auctions) are widely used as a model of situations where individuals devote resources to win some prize. In reality such contests are often preceded by investments of the contestants into their ability to fight in the contest. This paper studies a two stage game where in the first stage, players can invest to lower their bid cost in a perfectly discriminating contest, which is played in the second stage. Different assumptions on the timing of investment are studied. With simultaneous investments, equilibria in which players play a pure strategy in the investment stage are asymmetric, exhibit incomplete rent dissipation, and expected effort is reduced relative to the game without investment. There also are symmetric mixed strategy equilibria with complete rent dissipation. With sequential investment, the first mover always invests enough to deter the second mover from investing, and enjoys a first mover advantage. I also look at unobservable investments and endogenous timing of investments. Copyright © 2007 John Wiley & Sons, Ltd.     

Invader strategies in the war of attrition with private information

Second price all-pay auctions (wars of attritions) have an evolutionarily stable equilibrium in pure strategies if valuations are private information. I show that for any level of uncertainty there exists a pure deviation strategy arbitrarily close to the equilibrium strategy such that for some valuations the equilibrium strategy has a selective disadvantage against the deviation if the population mainly plays the deviation strategy. I show that agents with those valuations would prefer to deviate even farther from the equilibrium strategy, if the population collectively uses the deviation strategy. I argue that in the Bayesian game studied here, a mass deviation can be caused by the entry of a small group of agents. The results provided in this paper imply that the equilibrium strategy is indeed unstable if one considers rare and independent mutations on the space of valuations. Numeric calculations indicate that the closer the deviation strategy to the equilibrium strategy, the more valuations are destabilizing.     

Inconsequential arbitrage

We introduce the concept of inconsequential arbitrage and, in the context of a model allowing short-sales and half-lines in indifference surfaces, prove that inconsequential arbitrage is sufficient for existence of equilibrium. Moreover, with a slightly stronger condition of nonsatiation than that required for existence of equilibrium and with a mild uniformity condition on arbitrage opportunities, we show that inconsequential arbitrage, the existence of a Pareto optimal allocation, and compactness of the set of utility possibilities are equivalent. Thus, when all equilibria are Pareto optimal — for example, when local nonsatiation holds — inconsequential arbitrage is necessary and sufficient for existence of an equilibrium. By further strengthening our nonsatiation condition, we obtain a second welfare theorem for exchange economies allowing short sales.Finally, we compare inconsequential arbitrage to the conditions limiting arbitrage of Hart [Hart, O.D., 1974. J. Econ. Theory 9, 293–311], Werner [Werner, J., 1987. Econometrica 55, abs1403–1418], Dana et al. [Dana, R.A., Le Van, C., Magnien, F., 1999. J. Econ. Theory 87, 169–193] and Allouch [Allouch, N., 1999. Equilibrium and no market arbitrage. CERMSEM, Universite de Paris I]. For example, we show that the condition of Hart (translated to a general equilibrium setting) and the condition of werner are equivalent. We then show that the Hart/Werner conditions imply inconsequential arbitrage. To highlight the extent to which we extend Hart and Werner, we construct an example of an exchange economy in which inconsequential arbitrage holds (and is necessary and sufficient for existence), while the Hart/Werner conditions do not hold.     

Evolution of heterogeneous beliefs and asset overvaluation

I analyze a model in which different agents have different non-rational expectations about the future price and cash flows of a risky asset. The beliefs in the society evolve according to a very general class of evolution functions that are monotone; that is if one type has increased its share in the population then all types with higher profit should also have increased their shares. I show that the price of the risky asset converges to the risk-neutral fundamental price even though all agents in the economy are risk-averse. The risky asset thus becomes overvalued as compared to the equilibrium with rational expectations. The overvaluation is a result of the evolution of beliefs and does not rely on such asymmetric assumptions as short-sale constraints or optimistic bias.     

自媒体帮助控股股东在定向增发中获利了吗？

考察了上市公司控股股东如何利用自媒体信息披露在定向增发融资中调节股价的变化,从而获取额外收益的过程。研究发现：控股股东为使定向增发融资顺利进行,倾向于在定向增发准备期频繁发布自媒体信息,以抬高股价吸引外部投资者关注,并且当发行对象不包括控股股东时,通过发布自媒体信息来抬高股价的行为会更加显著;而在定增新股定价期间,定向增发对象包括控股股东的上市公司却会显著减少自媒体信息发文数量,以压低股票价格,帮助控股股东以较低对价购入定增股票。进一步分析发现：上市公司中机构投资者持股对控股股东定价期间压低股价的行为具有显著抑制作用。从自媒体信息披露这一崭新视角切入,证实了我国上市公司控股股东在定向增发过程中既有通过自媒体信息披露使定向增发吸引关注、满足融资需求的动机,又有利用自媒体信息披露降低控股股东参与定向增发的成本、对自身进行利益输送的动机;而机构投资者能够有效监督这一过程中大股东的利己行为。研究结论为加强对上市公司在定向增发中信息披露的监管,保护中小投资者利益提供了有益的启示。     

Stochastic processes of temporary equilibria : A note

The existence of invariant measures for Markov processes of temporary equilibria is derived under assumptions on demand and supply functions that allow the use of Doeblin's condition. This approach does not require the existence of a continuous selection of the temporary equilibrium correspondence.     

Trading equilibrium in a public good economy with smooth preferences and a mixed measure space of consumers

Lindahl and Nash equilibria are often used in the theory of public good. Shitovitz and Spiegel (1998) present an example of 2-person economy with one private good and one pure public good, where the core efficient Lindahl allocation does not Pareto dominate the (inefficient) Nash allocation. In this paper we introduce the new concept of Trading equilibrium for a general public good economy with smooth preferences and a mixed measure space of consumers. We obtain that this economy admits a unique Trading equilibrium. Moreover, the Trading equilibrium induces a core allocation that strictly Pareto dominates the Nash allocation.     

Bargaining through Approval

The paper considers two-person bargaining under Approval Voting. It first proves the existence of pure strategy equilibria. Then it shows that this bargaining method ensures that both players obtain at least their mean utility level in equilibrium. Finally it proves that, provided that the players are partially honest, the mechanism triggers sincerity and ensures that no alternative Pareto dominates the outcome of the game.     

Hierarchic competitive equilibria

Without an interiority or strong survival assumption, an equilibrium may not exist in the standard Arrow–Debreu model. We propose a generalized concept of competitive equilibrium, called hierarchic equilibrium. Instead of using standard prices we use hierarchic prices. Existence will be shown without a strong survival assumption and without a non-satiation condition on the preferences. Under standard assumptions this reduces to the Walras equilibrium. Hierarchic equilibria are weakly Pareto optimal and any Pareto optimum can be decentralized without a border condition. We prove the existence of a Pareto optimal hierarchic equilibrium under additional assumptions. Later, we establish a core equivalence result.     

Bargaining solutions with non-standard objectives

I examine the pure-strategy solutions of the sealed-bid bargaining game with incomplete information, when the buyer's and seller's objectives are other than the standard objective, namely maximization of expected profit. The motivation for this exploration lies in three problems of the standard formulation: the necessity of assuming common priors, the existence of uncountably many Nash equilibria, with no means for the players to coordinate on any one of them, and the uncertain relationship between these equilibria and observed behavior in bargaining experiments. Specifically, I consider two alternative objectives: minimization of maximum regret, and maximization of maximum profit. The solution concept here is not Nash equilibrium, but rather -individually rational strategy bundle. For that reason, I shall, where appropriate, use the word “solution” in place of “equilibrium.” Yet we find that the notion of Nash Equilibrium reappears, in a sense to be explained. In the minimax-regret case I find (in contrast to the case of expected profit) a unique solution; this solution reduces, for priors with coincident support, to the linear equilibrium of Chatterjee-Samuelson. In the maximum-profit case there are many solutions; they turn out to be slight generalizations of the one-step equilibria of Leininger-Linhart-Radner.     

Rationality-in-Relations

A BSTRACT . If in a game with multiple proper coordination equilibria there is a single one that is best for all participants, it is rational for each participant to choose the strategy that has the best equilibrium as one of its possible outcomes. This seems so obvious that any plausible theory of rationality should be expected to be applicable to such situations. However, this is not true for the "orthodox" theory of rational choice, as Robert Sugden has convincingly shown. In this paper, I shall argue that this failure is due to an implicit individualistic understanding of intentionality . John R. Searle's concept of collective intentionality (as put forth in his Construction of Social Reality ) and his more recent theory of Rationality in Action provides important conceptual tools pertaining to a more comprehensive theory of rationality. The account I shall develop differs from Searle's own, as for reasons to be found in his overall project, Searle's departure from the orthodox view of rationality gets stuck half-way.