县(市)级土地利用总体规划中耕地需求量预测方法及其应用

科学准确地预测耕地需求量,是制定县(市)级土地利用总体规划的基础.文章根据中国南方某县1996-2005年来的耕地变更调查统计数据,分别采用趋势分析法、回归分析法、指数平滑法、GM(1,1)模型法和灰色-马尔柯夫链模型的方法,对该地区耕地总量进行了模拟和预测.不同方法的预测结果表明,基于灰色-马尔柯夫链方法的预测结果更加准确可靠,更有利于土地管理决策者的经济决策行为.在当前耕地利用方式的背景下,灰色-马尔柯夫链模型可以作为县(市)级土地利用总体规划中耕地需求量预测方法的一种好选择.     

基于Repast平台的城市交通系统仿真建模研究

提出了采用基于Agent的仿真建模方法为研究人员提供了城市交通系统研究新的思路，Repast平台则可以支持研究人员对复杂适应系统快速地建模。介绍了Repast仿真平台的结构、主要类库及建模步骤，并结合城市交通系统中提供交通信息服务的实例，简要阐述了使用Repast仿真平台对城市交通系统进行建模的过程。     

基于期权定价理论的所有者与债权人代理问题分析

所有者和债权人之间的代理关系是现代公司治理的重要要素,如何理解和处理二者之间的关系成为社会关注的核心。本文从期权角度对所有者与债权人之间的代理关系进行新的理解,并分别介绍了无风险套期保值、B-S期权定价理论模型的具体运用以及保护债权人利益的具体措施。     

用期权定价模型评估企业并购的价值

针对传统企业并购价值评估模型的局限性,本文从期权的角度阐述了企业并购的期权特性,指出企业并购实质上相当于取得了一个看涨期权;并以连续支付红利的美式期权定价理论为基础,建立了企业并购价值评估的期权定价模型。最后,通过实例论述了如何应用该模型来评估企业并购价值,对实践中企业并购价值的合理确定具有重要的指导意义。     

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.     

基于不对称需求信息的激励机制模型研究

针对由单制造商和单销售商组成的供应链,提出了供应链双方需求信息对称情况下的激励机制模型,并在此基础上建立了供应链双方在需求信息不对称情况下的运作策略模型。制造商通过折扣,运用激励相容机制使销售商诚实申报需求信息,使得供应链利润最大化的同时供应链成员实现双赢。数字试验结果表明:①所提策略是有效的;②该策略不仅能提高制造商利润,而且也能改善销售商的利润。     

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.     

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。