Multi-stage sequential all-pay auctions

We study multi-stage sequential all-pay contests (auctions) where heterogeneous contestants are privately informed about a parameter (ability) that affects their cost of effort. We characterize the perfect Bayesian equilibrium of these contests and analyze the effect of the number of contestants and their types on the contestants׳ expected highest effort.     

The Formateurs’ Role in Government Formation

Following an election, Heads of State typically choose a formateur to report back a prospective government by some deadline. If this formateur fails then another party leader is chosen on the same terms. We model this mechanism as a bargaining game, in which a single party leader has exclusive access to the Head of State, but does not have a monopoly on making proposals. We characterize the unique equilibrium of the game in which all parties are symmetric and parties split a fixed-size pie. We also show that supra-minimal governments may form when parties are asymmetrically sized: a result consistent with the evidence on government formation in countries which use a formateur mechanism. We are grateful to Maria Montero, Rick Thomas and Paul Warwick for valuable conversations, and to seminar participants in UBC and Warwick.     

Banks,relative performance,and sequential contagion

We develop a multi-period general equilibrium model of bank deposit, credit, and interim inter-bank loan markets in which banks initially specialize in their choices of debtors, leading to under-diversification, but nevertheless become entwined via inter-bank markets, leading to the fortunes of one bank affecting the profits and default rates of the other in a sequential manner. Lack of (full) diversification among credit risks arises in our model owing to a relative profit argument in each banker’s utility function, which is otherwise risk- and default-averse. We examine its implications for the welfare of depositors and debtors. An erratum to this article can be found at     

阿奇霉素序贯疗法治疗小儿肺炎支原体肺炎临床疗效观察

目的探讨阿奇霉素序贯疗法治疗MPP的临床价值及优越性。方法将86例MPP患儿分为观察组（45例）和对照组（41例）,对照组给予红霉素静脉滴注治疗,观察组给予阿奇霉素序贯疗法治疗,观察两组患儿临床症状及体征改善情况,并进行疗效评定。结果观察组治疗总有效率为97.78%,明显高于对照组的82.93%（P＜0.05）;观察组临床症状和体征消失时间均低于对照组（P＜0.05）;观察组不良反应发生率为13.33%,明显低于对照组的34.15%（P＜0.05）。结论阿奇霉素序贯疗法治疗MPP具有疗效好、见效快、不良反应少等优点,是目前治疗小儿MPP的一种首选方案。     

序贯疗法在根除幽门螺杆菌的临床疗效评价

目的 评价序贯疗法根除幽门螺杆菌的效果和不良反应.方法 选取本院消化内科住院或门诊70 例Hp 阳性的患者,随机分为序贯治疗组和对照组,治疗组给予10 日序贯疗法,对照组给予标准三联疗法,疗程10 日,疗程结束后4 周行快速尿素酶试验和银染色.结果 治疗组的Hp 根除率明显优于对照组(P＜0.05),治疗组的快速尿素酶试验和银染色的转阴率分别为91.4%和82.3%,两组比较差异具有显著性(P＜0.05).结论 序贯疗法根除Hp 的效果好于标准三联疗法,副反应发生率低.     

Development and government policies of the shrimp farming industry in Thailand in relation to mangrove ecosystems

Intensive shrimp farming arrived in Thailand during the 1980s and developed virtually unregulated until 1987. Subsidised by the government, it quickly became an important export industry and Thailand has been the world's largest producer of tiger shrimp since 1991. However, the development of the shrimp farming industry in Thailand over the last 20 years in relation to its use of mangrove ecosystems is an example of sequential exploitation of natural resources witnessed through the shift in farm development from one region to another. This sequential exploitation has caused widespread degradation of mangrove ecosystems, and the benefits of the industry may be less than perceived as a result of subsidies and environmental and social impacts. This study follows the development of shrimp farming in Thailand from the 1940s to 1997 and studies national legislation and associated government policy as examples of driving forces behind this development. From our findings it appears that the development of legislation has not followed the same pace as the development of the industry, neither temporally, nor in content nor implementation, and contradictory policies have arisen.     

Sequential voting with abstention

Dekel and Piccione [2000. Sequential voting procedures in symmetric binary elections. J. Polit. Economy 108, 34–55] have proven that information cascades do not necessarily affect the properties of information aggregation in sequential elections: under standard conditions, any symmetric equilibrium of a simultaneous voting mechanism is also an equilibrium of the correspondent sequential mechanism. We show that when voters can abstain, these results are sensitive to the introduction of an arbitrarily small cost of voting: the set of equilibria in the two mechanisms are generally disjoint; and the informative properties of the equilibrium sets can be ranked. If an appropriate q-rule is chosen, when the cost of voting is small the unique symmetric equilibrium of the simultaneous voting mechanism dominates all equilibria of the sequential mechanism.     

Trees and decisions

Summary. The traditional model of sequential decision making, for instance, in extensive form games, is a tree. Most texts define a tree as a connected directed graph without loops and a distinguished node, called the root. But an abstract graph is not a domain for decision theory. Decision theory perceives of acts as functions from states to consequences. Sequential decisions, accordingly, get conceptualized by mappings from sets of states to sets of consequences. Thus, the question arises whether a natural definition of a tree can be given, where nodes are sets of states. We show that, indeed, trees can be defined as specific collections of sets. Without loss of generality the elements of these sets can be interpreted as representing plays. Therefore, the elements can serve as states and consequences at the same time.Received: 23 January 2003, Revised: 2 November 2003, JEL Classification Numbers: C72, D70. Correspondence to: Klaus RitzbergerWe are grateful to Larry Blume, Ariel Rubinstein, Jörgen Weibull, an anonymous referee, and seminar participants at the universities of Vienna, Salamanca, and Heidelberg for helpful comments. Financial support from the Austrian Science Fund (FWF) under project P15281 is also gratefully acknowledged.     

A general existence theorem for equilibrium price dispersions

This paper presents sufficient conditions for the existence of non-degenerate equilibrium price dispersions in economies with sequentially searching consumers. This existence result is obtained by fully utilizing the fixed-point property of equilibrium price dispersions. Compared with the existing literature, the formal framework used in this paper is very general. Consequently, the results of the paper are valid for a large class of economic models.     

Cass transversality condition and sequential asset bubbles

Summary. The objective of this paper is to illustrate the connection existing between the asymptotic value of a certain random series and the absence of asset pricing valuation bubbles in stochastic economies with sequential markets. This series, in turn, is closely related to the one proposed by Cass to characterize efficient accumulation paths in Solow models.Received: 3 June 2003, Revised: 3 March 2004, JEL Classification Numbers: C61, C62, D51, G12.A first draft of this paper was presented at the V Conference of the Society for the Advancement of Economic Theory, Ischia, Italy, 2001. I am grateful to S. Spear and an anonymous referee for their valuable comments. This research was partially supported by MIUR (Ministero dellIstruzione, Universitá e Ricerca).     

A sequential approach to regional integration: The European Union and Central and Eastern Europe

This paper develops a theory of optimal sequencing of regional integration and applies it to the specific question of Central and Eastern European countries (CEECs) and the EU. We show that the timing of transition and integration has implications for the long-term trade structure of Europe. In this model the interest to integrate the CEECs comes from harmonization of policies to attract industries. Without integration, European countries will try to inefficiently protect their industries. Because of the transfers implied by the CAP and the Structural Policies, the EU delays enlargement until the CEECs have sufficiently converged. CEECs might at this point prefer to stay outside the EU and attract industries by offering them more generous protection than the EU. Such timing may be inefficient ex ante for all countries because it may prevent full European integration in the long run, inducing firms to relocate outside of the EU and governments in the EU and the CEECs to inefficiently protect industry. During the transition, all countries benefit from regional integration among the CEECs.     

Conditions for equivalence between sequentiality and subgame perfection

We characterize the class of finite extensive forms for which the sets of Subgame Perfect and Sequential equilibrium strategy profiles coincide for any possible payoff function. In addition, we identify the class of finite extensive forms for which the outcomes induced by these two solution concepts coincide. We thank Luis Corchón, Francesco De Sinopoli, Herbert Gintis, Sjaak Hurkens, Francisco Marhuenda, Eric Maskin and four anonymous referees for helpful comments. Carlos thanks the financial support of the Spanish MEC through its FPI Grant BES-2003-0822. Cristian thanks the grant Plan de Formación de Personal Investigador de la Comunidad de Madrid and the financial support from project No. SEJ2004-00968/ECON from the Spanish Ministry of Education and Science. The usual disclaimer applies.     

Sequential negotiations with costly information acquisition

Negotiations about a merger or acquisition are often sequential and only partially disclose to bidders information about each otherʼs bids. This paper explains the seller optimality of partial disclosure in a single-item private-value auction with two bidders. Each bidder can inspect the item at a nonprohibitive cost. If a revenue-maximizing seller cannot charge bidders for the information about the otherʼs bid, then the seller optimally runs a sequential second-price auction with a reserve price and a buy-now price. The seller prefers to keep the bids confidential and, sometimes, to hide the order in which he approaches the bidders.     

Non-revelation mechanisms in many-to-one markets

In this study we present a simple mechanism in a many-to-one matching market where multiple costless applications are allowed. The mechanism is based on the principles of eligibility and priority and it implements the set of stable matchings in Subgame Perfect Nash Equilibrium. We extend the analysis to a symmetric mechanism where colleges and students interchange their roles. This mechanism also implements the set of stable matchings.     

Rationalizability and equilibrium in N-person sequential bargaining

Summary. This paper deals with N-person sequential bargaining games with complete information. For N-person sequential bargaining games, uniqueness of the SPE has been obtained by allowing the players to exit with partial agreements. Adopting a non-equilibrium approach, we show that N-person sequential bargaining games with exit are solvable by a refinement of rationalizability for multi-stage games (trembling-hand rationalizability) whatever the impatience of the players. That is, once we adopt the non-equilibrium approach, the exit opportunity still fulfils its original aim: we achieve a unique solution by introducing the exit opportunity. Moreover, this unique solution is the unique SPE. Received: October 30, 1996; revised version: July 7, 1998     

Regularity of pure strategy equilibrium points in a class of bargaining games

Summary. We develop an index theory for the Stationary Subgame Perfect (SSP) equilibrium set in a class of n-player sequential bargaining games with probabilistic recognition rules. For games with oligarchic voting rules (a class that includes unanimity rule), we establish conditions on individual utilities that ensure that for almost all discount factors, the number of SSP equilibria is odd and the equilibrium correspondence lower-hemicontinuous. For games with general, monotonic voting rules, we show generic (in discount factors) determinacy of SSP equilibria under the restriction that the agreement space is of dimension one. For non-oligarchic voting rules and agreement spaces of higher finite dimension, we establish generic determinacy for the subset of SSP equilibria in pure strategies. The analysis also extends to the case of fixed delay costs. Lastly, we provide a sufficient condition for uniqueness of SSP equilibrium in oligarchic games.Received: 13 May 2004, Revised: 1 March 2005, JEL Classification Numbers: C62, C72, C78.I thank John Duggan and participants of the 2003 annual meeting of the American Political Science Association, Philadelphia, PA, the Political Economy Seminar at Northwestern University, and the Economic Theory seminar at the University of Rochester for helpful comments.     

广告主与搜索引擎的双向博弈分析

文章基于萨缪尔森的双向叫价博弈模型,对关键词广告拍卖中的一类特殊情形进行研究—某些关键词广告的拍卖中只有一个广告主进行竞价。假设买方的估价是广告主的私有信息,而广告位的成本也是搜索引擎的私有信息,建立一个广告主和搜索引擎的双向叫价非完全信息贝叶斯博弈模型。在假设双方的报价策略均是自己估价的线性函数的条件下,求解了使广告主和搜索引擎收益最大化的贝叶斯纳什均衡,给出了广告主和搜索引擎的均衡报价策略,分析了拍卖能够达成时双方交易的效率,并得到了效率最高时双方的最优出价策略及最高效率。当广告主和搜索引擎第一次博弈不能达成交易时,双方会通过多次重复谈判和协商,经过多轮的重复报价序贯博弈达成最终交易,给出了双方序贯博弈的均衡报价策略;还给出了拍卖序贯博弈的交易流程图和一些数值算例。研究结果对广告主和搜索引擎的报价策略提供了理论参考依据。     

Stability,sequential rationality,and subgame consistency

In this paper we analyze dynamic strategic behavior by means of the idea of "stability." We develop a solution concept of "sequentially stable equilibrium (SSE)" that satisfies subgame consistency. All SSEs are characterized by the largest stable set that yields exactly all the backward induction outcomes. We also provide a refinement of the SSE. We compare the SSE and its refinement with some existing solution concepts in the literature We are grateful to the editor and two anonymous referees for very useful comments and suggestions that led to this revision. We thank Chih Chang, Yi-Chun Chen, Chenying Huang, Huiwen Koo, Man-Chung Ng, Shyh-fang Ueng, and Chun-Hsien Yeh for helpful comments and discussions. We also thank participants in seminars at Academia Sinica, National Dong Hwa University, and the Third Pan-Pacific Game Theory Conference. Financial support from the Social Sciences and Humanities Research Council of Canada (SSHRC), the National Science Council of Taiwan, and the Economic and Social Research Council of the UK is gratefully acknowledged. The usual disclaimer applies.     

上市公司可转换债券融资的动机分析——基于连续融资假说的实证检验

本文以我国2002-2006年期间董事会公告发行可转债的上市公司为样本,运用事件研究法和多元回归方法验证我国上市公司发行可转债是否符合连续融资假说.实证结果表明:业务集中度、转股价格以及公司对发行成本的敏感度三个变量都与公司公告发行可转债的市场反应正相关,但其结果在统计意义上均不显著,这说明连续融资假说理论还不足以解释我国上市公司发行可转债的动机.