Tax Effects in a Model of Product Differentiation: A Note

We investigate how unit (or specific) tax and ad valorem tax affect equilibrium location choice in a model of product differentiation, which includes Hotelling (linear-city) and Vickrey-Salop (circular-city) spatial models as special cases. We find that neither tax affects equilibrium location patterns as long as each firm has the same production cost. Two taxes can yield different location patterns under cost heterogeneity among firms.     

Giffen goods and market making

Summary. This paper shows that information effects per se are not responsible for the Giffen goods anomaly affecting traders demands in multi asset noisy, rational expectations equilibrium markets. The role that information plays in traders strategies also matters. In a market with risk averse, uninformed traders, informed agents have a dual trading motive: speculation and market making. The former entails using prices to assess the effect of error terms; the latter requires employing them to disentangle noise traders demands within aggregate orders. In a correlated environment this complicates the signal extraction problem and may generate upward sloping demand curves. Assuming (i) that competitive, risk neutral market makers price the assets or that (ii) uninformed traders risk tolerance coefficient grows unboundedly, removes the market making component from informed traders demands rendering them well behaved in prices.Received: 30 April 2002, Revised: 3 December 2003, JEL Classification Numbers: G100, G120, G140.Support from the Barcelona Economics Program of CREA and the Ente per gli Studi Monetari e Finanziari Luigi Einaudi, are gratefully acknowledged. I thank Anat Admati, Jordi Caballé, Giacinta Cestone, and Xavier Vives for useful suggestions. The comments provided by the Associate Editor and an anonymous referee greatly improved the papers exposition.     

Market clearing and derivative pricing

Summary. We develop a method of assigning unique prices to derivative securities, including options, in the continuous-time finance model developed in Raimondo (2001). In contrast with the martingale method of valuing options, which cannot distinguish among infinitely many possible option pricing processes for a given underlying securities price process when markets are dynamically incomplete, our option prices are uniquely determined in equilibrium in closed form as a function of the underlying economic data.Received: 14 April 2003, Revised: 7 January 2004, JEL Classification Numbers: G13, D52.This paper is dedicated to Birgit Grodal, whose strength and character we greatly admire. We are very grateful to Darrell Duffie, Steve Evans, Botond Koszegi, Roger Purves, Jacob Sagi, Chris Shannon, Bill Zame and an anonymous refereee for very helpful discussions and comments. The work of both authors was supported by Grant SES-9710424, and Andersons work was supported by Grant SES-0214164, from the National Science Foundation.     

完善我国上市公司治理结构的路径选择

本考证了两种典型的公司治理模式的特征，效率和演变趋势，结合我国上市公司的股权结构分析了公司治理结构，并得出结论：现实的国情和西方公司治理的演变趋势决定了完善我国上市公司治理结构的路戏只能是首先完善公司内部治理结构，未来应朝着以内部治理的主、外部治理为辅的博采众长的混合模式的方向发展。     

股权分置改革对流通股股东补偿问题的研究

股权分置改革是当前我国资本市场的热点问题，实施股权分置改革试点上市公司的股权分置改革方案的出台，更引起了广泛的关注。本文运用量化分析模型对股权分置改革中有关流通股股东的补偿问题进行了研究，得出了补偿的合理性是影响流通股股东对方案认可的重要因素这一结论，并结合实施股权分置改革试点上市公司所推出的具体方案进行了验证。     

Pro-cyclical effect of sovereign rating changes on stock returns: a fact or factoid?

This article examines the effect of changes in sovereign credit ratings and their outlook on the stock market returns of European countries at different phases of business cycle. Using standard four-factor model, it records a significant average marginal effect of credit rating announcements on stock market returns. Both magnitude and significance of the effect vary with business cycle and across announcement types. However, we do not find evidence of pro-cyclical effect of sovereign rating and outlook changes on stock returns. Our results show that stock markets react more negatively to rating downgrades in recovery phases and more positively to rating upgrades in contractionary period. Both results are statistically significant and robust to various sensitivity tests.     

股市新文化理论初探

长期以来,我国资本市场理论的研究落后于资本市场发展的实践。当前我国股市面临的一个突出问题是股市基础理论探讨严重匮乏。解决这一问题,需要从两个环节入手:第一是在社会主义市场经济条件下,对股市的基本功能进行探讨;第二是建立股市新文化和股权文化。     

最优再保险的期权博弈分析

期权博弈理论把期权定价和博弈论结合起来分析在连续时间和不确定性下的动态多人决策问 题。本文运用这种方法首先分析了超额损失再保险的期权特性,用期权定价技术为其定价,然后构建一个 完全信息动态博弈模型分析了原保险人和再保险人的最优策略和均衡结果,给出了无套利条件下的最优超 额损失再保险。与传统精算及其它经济分析文献不同,在此框架下得到的最优再保险保费体现了市场因 素,并反映了利益冲突的保险主体之间顺序动态决策的事实。     

金融中介及关系银行——基于广东外资企业银行融资数据的研究

本文根据外资银行和国有商业银行向在中国境内的外资企业提供的外币贷款和人民币贷款的数据 ,对金融中介及关系银行进行了实证研究。我们的主要结论有两点 :第一 ,企业与银行建立起来的金融业务关系越长久 ,那么其所获得的外币贷款利率就越低。这是对金融中介理论的支持。另外 ,外资控股、第三方担保等因素 ,也具有降低外币贷款利率的效应。第二 ,人民币贷款的利率随着外资企业与更多的银行建立和保持合作关系而降低。人民币贷款主要是由我国商业银行提供。如果商业银行间的竞争仅仅是用来作为信贷定价的主要决定因素 ,而不是用来推进金融创新 ,提供高质量的金融产品和服务 ,那么这将会损害我国商业银行的获利能力并进而影响金融系统的健康发展。     

上市公司股权激励问题研究

以现代企业理论和人力资本理论为基础的股权激励,有助于完善公司治理结构.文章论述了股权激励的理论基础、在我国发展情况以及推行的难点问题.结合目前我国股权分置改革,设计了股权激励的业绩评价指标和内在价值体现指标,提出了利用业绩和内在价值体现两个指标对激励对象进行综合评价的观点.