Manipulation of the Walrasian mechanism in production economies with unbounded short-selling

Hurwicz (1979) and Otani and Sicilian (1982, 1990) characterized the Nash equilibrium allocations of the Walrasian demand manipulation game in successively more general exchange environments. In this paper, I extend the analysis to production economies with short-selling. First, I generalize Hurwicz’s and Otani and Sicilian’s theorem that any allocation at which each agent’s consumption bundle lies above her true offer curve can be supported in Nash equilibrium. I then show that for finite economies of any size the set of such allocations is often topologically large.Received: 17 January 2003, Accepted: 4 April 2005, JEL Classification: D51, D82For comments on this and earlier versions of the paper, I wish to thank Rick Bond, Bhaskar Chakravorti, Tom Gresik, Costas Syropoulos and William Thomson. I would especially like to thank Mike Jerison for helping to overcome a difficulty with a previous version. Also, the comments of the anonymous referees are gratefully acknowledged.     

Non-manipulability in Walrasian cost games

JEL classification: D41, D51 Received: 24 December 1999 / Accepted: 18 October 2001     

Robust efficiency in mixed economies with asymmetric information

In this paper, we study robustly efficient allocations in a pure exchange economy. Answering a question of Hervés-Beloso and Moreno-García (2008), we present an extension of their main result to an asymmetric information mixed economy whose commodity space is an ordered separable Banach space having an interior point in its positive cone.     

The veto mechanism in atomic differential information economies

We establish new characterizations of Walrasian expectations equilibria based on the veto mechanism in the framework of differential information economies with a complete finite measure space of agents. We show that it is enough to consider the veto power of a single coalition, consisting of the entire set of agents, to obtain the Aubin private core. Moreover, we investigate on the veto power of arbitrarily small and big coalitions, providing an extension to mixed markets of well known Schmeidler (1972) and Vind’s (1972) results in terms of Aubin private core allocations.     

The equilibrium set of infinite dimensional Walrasian economies and the natural projection

The natural projection plays a fundamental role to understand the behavior of the Walrasian economies. In this paper, we extend this method to analyze the behavior of infinite dimensional economies. We introduce the definition of the social equilibrium set, and we show that there exists a bijection between this set and the Walrasian equilibrium set of an infinite dimensional economy. In order to describe the main topological characteristics of both sets, we analyze the main differential characteristics of the excess utility function and then, we extend the method of the natural projection as suggested by Y. Balasko.     

Existence of an equilibrium for infinite horizon economies with and without complete information

This work proves the existence of an equilibrium for an infinite horizon economy where trade takes place sequentially over time. There exist two types of agents: the first correctly anticipates all future contingent endogenous variables with complete information as in Radner [Radner, R. (1972). Existence of equilibrium of plans, prices and price expectations in a sequence of markets. Econometrica, 289–303] and the second has exogenous expectations about the future environment as in Grandmont [Grandmont, J. M. (1977). Temporary general equilibrium theory. Econometrica, 535–572] and information based on the current and past aggregate variables including those which are private knowledge. Agents with exogenous expectations may have inconsistent optimal plans but have predictive beliefs in the context of Blackwell and Dubbins [Blackwell, D., Dubins, L. (1962). Merging of opinions with increasing information. The Annals of Mathematical Statistics, 882–886] with probability transition rules based on all observed variables. We provide examples of this framework applied to models of differential information and environments exhibiting results of market selection and convergence of an equilibrium. The existence result can be used to conclude that, by adding the continuity assumption on the probability transition rules, we obtain the existence of an equilibrium for some models of differential information and incomplete markets.     

Lending terms and aggregate productivity

Several empirical studies suggest that lending terms are eased in expansions and tightened in recessions, thereby influencing the mix of financed entrepreneurs. We study a model of adverse selection in competitive financial markets and show that lending terms deteriorate with the aggregate state under two general conditions. If exogenous increments to entrepreneurs׳ productivity raise returns to investment and/or tighten the credit line needed to screen out a given entrepreneur type, competition results in contracts with less screening. Two endogenous effects on productivity emerge. Production scales grow closer to optimal, but lower productivity entrepreneurs enter the mix of producers. The positive (negative) effect dominates at low (high) aggregate states.     

A strong incompatibility between efficiency and equity in non-convex economies

In allocation problems of perfectly divisible goods, we study the equity property of ‘no-domination', according to which no agent can receive strictly more of all goods than any other agent. We prove that no-domination is incompatible with Pareto efficiency, as soon as preferences are allowed to be non-convex.     

Heterogeneity of technological regimes and banking efficiency in former socialist economies

Cost efficiency of banks in 20 former socialist emerging economies is analyzed using a latent class stochastic efficiency frontier model that explicitly accounts for unobserved differences in technological regimes due to the heterogeneity of economic environments in which the banks are operating. We find that banking systems in former socialist emerging economies are characterized by three distinct technological regimes. Based on the estimated efficiency scores we group the countries into three categories and provide an intuitive interpretation of these three regimes.     

Welfare and efficiency in incomplete market economies with a single firm

In the quasilinear case, surplus maximization leads to constrained efficient Drèze equilibria. We investigate the question of whether surplus maximization can be useful beyond the quasilinear case.     

Tiebout's tale in spatial economies: Entrepreneurship, self-selection, and efficiency

This paper establishes the existence and efficiency of equilibrium in a local public goods economy with spatial structures by formalizing Hamilton's [Hamilton, B.W., 1975. Zoning and property taxation in a system of local governments Urban Studies 12, 205–211] elaboration of Tiebout's [Tiebout, C., 1956. A pure theory of local public expenditures. Journal of Political Economy 64, 416–424] tale. We use a well-known equilibrium concept from Rothschild and Stiglitz [Rothschild, M., Stiglitz, J.E., 1976. Equilibrium in competitive insurance markets: an essay on the economics of imperfect information. Quarterly Journal of Economics 40, 629–649] in a market with asymmetric information, and show that Hamilton's zoning policy plays an essential role in proving the existence and efficiency of equilibrium. We use an idealized large economy following Ellickson, Grodal, Scotchmer and Zame [Ellickson, B., Grodal, B., Scotchmer, S., Zame, W.R., 1999. Clubs and the market, Econometrica 67, 1185–1217] and Allouch, Conley and Wooders [Allouch, N., Conley, J.P., Wooders, M.H., The Tiebout Hypothesis: On the Existence of Pareto Efficient Competitive Equilibria, (2004), mimeograph]. Our theorem is directly applicable to the existence and efficiency of a discrete spatial approximation of mono- or multi-centric city equilibria in an urban economy with commuting time costs, even if we allow the existence of multiple qualities of (collective) residences, when externalities due to traffic congestion are not present.     

Information precision and asymptotic efficiency of industrial markets

I present a strategic model of a bilateral oligopoly with asymmetric information to examine (i) the validity of the conjecture of price-taking behavior in such markets as the number of agents becomes large and (ii) the effect of the rate that individual information precision decreases with increased number of agents on convergence to price-taking and efficiency. I show that with downstream competition, increasing the number of sellers may make all participants price-takers in the limit, but increasing the number of buyers may not. When the total precision of information in the market is high, price-taking and full social efficiency is achieved in the limit with large numbers of buyers and sellers. However, if the total precision of information in the market is poor, price-taking conjecture may fail and large inefficiencies, including full inefficiency, can occur in the limiting outcome. The rate of decrease of individual information precision with increased number of agents determines the rate of convergence to efficiency, and the convergence is slower than that predicted by single-unit auction models in the literature. I also demonstrate that when the number of sellers or both the number of buyers and the sellers go to infinity, price-taking and information aggregation tend to go together. When the number of buyers goes to infinity, however, information can get aggregated when the agents do not become price-takers in the limit. Albeit, in the latter case, the aggregated information is masked by the noise in the sellers’ signals and the cost variability.     

The role of asset testing in public health insurance reform

Starting slowly with the 1996 Welfare Reform Act and culminating in the 2010 Affordable Care Act, means-tested public health insurance eligibility expanded to include adults in low-income families regardless of their asset holdings. This paper quantifies the effects of these eligibility expansions within the context of the 2010 Affordable Care Act. I construct a dynamic stochastic general equilibrium model with indivisible labor supply expanded to include an endogenous household choice of health insurance coverage and calibrate it to U.S. data. I establish that changes in the distribution of labor and welfare associated with removal of asset testing are driven by exit of high productivity and high wealth households from the labor market. I then expand my analysis to the 2010 Affordable Care Act to demonstrate that removal of asset testing is critical to the obtained results even when combined with other provisions of the Act. Finally, I find that a simple asset test for eligibility of health insurance transfers undoes the distortion to the household labor supply decision among high productivity types. These results are robust to the introduction of employer premium contributions, an independent health insurance market, and idiosyncratic shocks to eligibility for employment-based health insurance.     

Deregulation and liberalization of the Chinese stock market and the improvement of market efficiency

This study employs single and multiple variance ratio tests to reexamine the weak-form efficient market hypothesis (EMH) of A- and B-shares on the Shanghai and Shenzhen exchanges in Chinese stock market. The study also examines the influence of the release of investment restriction of B-share markets on market efficiency. For the whole sample period, the weak-form EMH is only supported for Shanghai A-shares, and is not supported for the remaining shares. For the sub-sample period, the Shenzhen A-share and B-shares of both exchanges being rejected for the weak-form EMH in the earlier sample period are supported following the regulatory change. Rolling multiple variance ratio test statistic values provide additional evidence of weak-form EMH. The improvement of market efficiency can be explained by the increased liquidity and maturity accompanying deregulation and liberalization.     

The relation between sunspot effects and multiplicity in incomplete markets models with numeraire assets

This paper considers the necessity and sufficiency of multiple certainty equilibria for sunspot effects, and shows that neither implication is valid. This claim is made for models with incomplete markets and numeraire assets. First, I prove that a multiplicity of certainty equilibria is neither necessary nor sufficient for sunspot effects by way of two counter-examples. Second, I verify over an entire subset of economies that equilibrium with sunspot effects can never be characterized as a randomization over multiple certainty equilibria.     

Firms' investments in general training and the skilled labour market

An adverse selection model is analysed, where firms can train or hire a skilled worker. In equilibrium, the market wage is determined by supply and demand. The quality of the supplied skilled labour is negatively biased, because workers stem from firms that shut down and from firms that observed their trainee's bad quality during the training. If fewer firms were to shut down, then the supplied average quality deteriorates and the incentive to train increases. The incentive is inefficient, because firms must share the informational rent and they free-ride. Ex ante workers may wish to increase the firms' bargaining power.     

Bargaining and exclusivity in a borrower–lender relationship

This paper presents a stylized model of a borrower–lender relationship where funds are gradually invested in a project with uncertain return. We show that an exclusive financing relationship arises endogenously in equilibrium due to initial lender’s superior information on the project’s progress. The analysis also identifies a novel distortionary effect of exclusivity and the consequent loss of future rents on the ex-ante choices of the borrower. When she chooses the amount of funds to be initially invested in the project, the borrower chooses to overinvest making the future rent extraction by the initial lender as costly as possible. We would like to thank Alberto Bisin, Andrew Chen, Boyan Jovanovic, Hideo Konishi, David Mauer, Efe Ok, Mike Riordan, Charles A. Wilson, and seminar participants at Society of Economic Design 2002 meetings in New York and Southern Methodist University for helpful comments. The usual disclaimer applies.     

Ownership structure and firm performance in emerging markets: A comparative meta-analysis of East European EU member states,Russia and China

Using a total of 4425 estimates collected from 204 previous studies, this paper presents a meta-analysis performed to compare East European EU member states, Russia and China in terms of the relationship between ownership structure and firm performance. The results indicate that, as the standard theory predicts, state ownership negatively influences the performance of firms the state invests in, while the presence of domestic outside investors and foreign investors as company owners positively affects firm performance irrespective of the difference in country/region. Furthermore, we also found that ownership of managers tends to exert a positive impact on the performance of their owned firms. Overall, however, the linkage between corporate ownership and performance is weak. This finding implies that, in comparison with advanced economies, management discipline by investors is less sufficient in emerging markets.     

信息不对称与中小企业融资问题

中小企业在我国已成为国民经济的重要组成部分。但是,随着商业银行加强对贷款风险的控制,普遍实行担保和抵押制,中小企业融资难问题日益突出。造成这一矛盾的根本原因在于中小企业与金融机构之间严重的信息不对称,中小企业由于自身信誉差、信息内部化,银行不能准确判断筹资者真实情况而惜贷。解决的根本途径在于全社会健全信用系统,促使中小企业树立诚信观念,提高资金使用效益,还贷守信。同时,还需要政府、金融机构共同努力协作,成立中小企业管理机构,建立中小企业发展基金,完善专门的贷款担保机构,有效解决信息不对称问题,改善中小企业融资环境。