Microeconomics Workshop 2003

※ 21世紀COEプログラムと共催 ※


※ 3月25日現在　近い予定から順に掲載しています。本年度のワークショップは終了いたしました。

※ 以下本年度終了分
※4月8日はワークショップはありません No Workshop on April 8.

日時：
4月15日（火）16:50-18:30 **Presentation in English
場所：
東京大学経済学研究科棟第3教室（経済学部新棟３階）
at the Lecture Hall C(=No.3) on the 3rd floor of New Econ. Building
報告：
Fuhito Kojima 小島武仁(University of Tokyo 東京大学)
Risk-Dominance and Perfect Foresight Dynamics in N-Player Games
Abstract:
We investigate perfect foresight dynamics, a dynamic process of equilibrium selection formalized by Matsui and Matsuyama (1995). People are assumed to play random matching games and make rational decisions. Stability concepts under this dynamics are defined. We also introduce the concept of f-dominance, which is a generalization of risk-dominance. We show that stability under perfect foresight dynamics, which is dynamical in nature, is guaranteed in terms of f-dominance, which is a static stability concept. Then we apply this general result to special classes of games: games that have p-dominant equilibria with small p: quasi-bandwagon games (a class which includes supermodular games and marginal bandwagon games). For these games we obtain several selection criteria which are simple and useful. Several known theorems, as well as new results, are obtained as corollaries of the general result. Thus this paper unifies, as well as generalizes, a number of selection criteria.
日時：
4月22日（火）16:50-18:30
場所：
東京大学経済学研究科棟第3教室（経済学部新棟３階）
at the Lecture Hall C(=No.3) on the 3rd floor of New Econ. Building
報告：
Kazuya Kamiya 神谷和也 (University of Tokyo 東京大学)
Random Matching Models and Money: The Global Structure of the Set of Stationary Equilibria, joint with Dolf Talman
Abstract:
Random matching models with states are an important class of dynamic games; for example, money search models, job search models, and some games in biology are special cases. In this paper, we investigate the basic structure of the models: the existence of equilibria, the global structure of the set of equilibria, and the approximation and computation of equilibria. It is worthwhile noting that, under some conditions which are typically satisfied in monetary models, the equilibrium condition can be considered as a complementarity problem with a new feature.
日時：
5月6日（火）16:50-18:30 **Presentation in Japanese
場所：
東京大学経済学研究科棟第3教室（経済学部新棟３階）
at the Lecture Hall C(=No.3) on the 3rd floor of New Econ. Building
報告：
Keizo Mizuno 水野敬三(School of Business Administration, Kwansei Gakuin University 関西学院大学)
From Access to Bypass: A Real Options Approach (joint with Keiichi Hori, Ritsumeikan University)
Abstract:
This paper examines firms' incentives for irreversible investments in net-work industries under uncertainty. We characterize an entrant's strategy choice in terms of an access charge premium and an incremental profit flow accrued from access to bypass. It is then shown that an introduction of com-petition in network industries contributes to an enhancement of consumer welfare in a sense that the timing of entry becomes earlier with competition than without competition. In addition, we ensure that allowing the oppor-tunity to have access to an incumbent's network facility makes an entrant's incentive to construct a bypass network weak. The e ect of access charge on the investment timing is also discussed.
日時：
5月13日（火）16:50-18:30
場所：
東京大学経済学研究科棟第3教室（経済学部新棟３階）
at the Lecture Hall C(=No.3) on the 3rd floor of New Econ. Building
報告：
Xu Peng 胥鵬(Hosei University 法政大学)
Bankruptcy Resolution in Japan: Corporation Reorganization vs. Civil Rehabilitation
Abstract:
I present new evidence on recent bankruptcy resolution and bankruptcy legal reform in Japan. Prior to bankruptcy, bank lenders are less likely to intervene than they did before. Most bankrupt firms experience abnormal senior management turnover around bankruptcy filings, regardless types of filings. Priority of claims is less violated in bankruptcy resolution than that in the United States. Moreover, a bankrupt firm spends less time in bankruptcy under Civil Rehabilitation Law than under Corporate Reorganization Law, after bankruptcy law reform in 2000. This study complements previous studies, which investigate private debt restructurings initiated by bank lenders till the 1980s.
日時：
5月20日（火）16:50-18:30
場所：
東京大学経済学研究科棟第3教室（経済学部新棟３階）
at the Lecture Hall C(=No.3) on the 3rd floor of New Econ. Building
報告：
Yutaka Suzuki 鈴木豊(Hosei University 法政大学)
A Contract Theoretic Analysis on "Relational Contracting Between and Within Firms": "Managed Competition as an Incentive Mechanism in Supply Relations" and "Commitment Problem, Optimal Incentive Schemes, and Relational Contracts in Agency with Bilateral Moral Hazard" PAPER 1     PAPER 2
Abstract:
In this talk, under the motivation of " Relational Contracting between and within firms", we present two papers on "outsourcing" and "employment", though mainly focusing on the first one.
The first paper theoretically examines a procurement form in supply relations, called 'Managed Competition', where a principal (buyer) uses dynamic competition between two agents (suppliers) to maximize its payoff. The principal commits to an incentive scheme at the beginning, and assigns the production share in the final period, according to the interim rank of the level of capital accumulation. By that, an asymmetric equilibrium favorable to the winner is generated in the subsequent stage, which in turn creates a tournament effect through a discrete prize in the first period, in addition to a marginal strategic effect. We characterize the optimal solution to the overall problem (a Kuhn-Tucker problem with static and dynamic incentive constraints) faced by the principal, and investigate some conditions, under which the principal wants to induce ex post competition among agents actively, under which she doesn't induce such competition and restrains procurement from the loser, and under which she chooses not to intervene in the form of 'allotment', even with observability of the progress along the way among agents. These solutions imply that the principal endogenously chooses the mode of competition, depending upon the exogenous conditions. This kind of intervention mechanism not only promotes accumulation of relation specific skills, but also induces it in a less costly manner. It also explains an aspect of efficiency in managed supplier organization in the Japanese automobile industry (as a typical example, two supply policy and design in of Toyota), essential aspects of which, in the 1980's and early 1990's, the Big Three in the United States automobile industry (GM, Ford, Chrysler) had tried to learn and adopt.
In the second paper, we consider a bilateral moral hazard framework, where the principal is also a productive agent, and the two requirements on both the agent's and the principal's incentive provisions should be satisfied in designing optimal incentive contracts. In the static framework, only the second best is obtainable if the incentive contract should be based only on the total output. An example is the simple linear sharing rule often observed. Next, we show that in a repeated game version, such commitment problem could be solved, and a first best outcome could be achieved through both parties taking trigger strategies depending on a public signal. We give an interpretation in the viewpoint of 'reputation' mechanism, and a qualitative characterization on the optimal solution induced in equilibrium for "all" possible discount factors.
日時：
5月23日（金）16:50-18:30 ※ 曜日と場所が通常と異なりますのでご注意下さい。
場所：
東京大学経済学研究科棟第2教室（経済学部新棟３階）
at the Lecture Hall B(=No.2) on the 3rd floor of New Econ. Building
報告：
In Ho Lee(Seoul National University)
Uncertainty, Coordination and Path Dependence (joint with Robin Mason, University of Southampton)
Abstract:
This paper shows how uncertainty and heterogeneity together resolve the difficulty of coordi-nation in an economy which is subject to strategic complementarity. We construct an economy where the outcome of economic activity depends on the number of agents who choose a certain action as well as the realization of underlying state of nature. The economy may possess multiple equilibria if all agents make decision at once. On the other hand they may be able to resolve the difficulty of multiplicity, if agents make decisions in a sequential fashion. The dynamic economy with sequential choice exhibits path dependence where the order of signal arrival matters; if good news arrives early, the economy obtains better outcome while the economy fares worse when the order of signal is reversed. The multiplicity of equilibrium manifests itself in the dynamic model in that the same set of signals may result in different outcomes depending on the order of arrival.
日時：
5月26日（月）16:50-18:30 ※ 曜日と場所が通常と異なります。場所が変更になっていますのでご注意下さい。
場所：
東京大学経済学研究科棟第1共同研究室（経済学部新棟12階）
at the Conference Room A(=No.1) on the 12th floor of New Econ. Building
報告：
Serguey Braguinsky(State University of New York at Buffalo)
Investment with Imperfect Property Rights (joint with Roger Myerson)
Abstract:
We consider an economy where productive capital can be owned only by the members of an elite politically-connected oligarchy and property rights and contracts are enforced through private protection and political support rather than through a public legal system. This private protection entails a degree of security of ownership that is good but not perfect. The performance of the economy will depend critically on oligarchs' ability to ensure themselves against political risks by issuing financial claims against their capital assets. When political risks can be shared in this way, we find that free-market reforms can stimulate economic growth. But when distrust among oligarchs prevents their political risk-sharing, we find that free-market reforms can cause a severe contraction that resembles the actual Russian experience in the 1990s. To obtain these results, we compare models in which the overall risk of capital expropriation is the same, changing only our assumptions about the degree to which oligarchs can share these risks. The model is calibrated to fit some of the Russian macroeconomic data.
日時：
5月27日（火）16:50-18:30CANCELLED 本日の発表はキャンセルになりました。
報告：
Hitoshi Matsushima 松島斉(University of Tokyo 東京大学)
Honesty-Proof Implementation CIRJE Discussion Paper 2002cf178
Abstract:
We investigate implementation of social choice functions that map from states to lotteries and may depend on factors other than agents' preferences. We assume that agents are not only purely self-interested but also honesty-oriented in a lexicographical way. We define iterative honesty-proofness by iteratively removing messages dominated by more honest messages. We show that in the complete information environments with small fines, every social choice function is implementable in iterative honesty-proofness. This is in contrast with the standard implementation model, because any 'normative' social choice function depending on non-preference factors is never implementable when agents are not influenced by factors other than pure self-interest. We extend this result to the incomplete information environments with quasi-linearity and with correlated private signals.
Next, we assume that it is costly for each agent to report dishonestly and this cost may be close to zero. We show that in the incomplete information environments, every incentive compatible social choice function can be implemented by the mechanism that is universal in the sense that it does not depend on the private signal structure.
日時：
6月3日（火）16:50-18:30
場所：
東京大学経済学研究科棟第3教室（経済学部新棟3階）
at the Lecture Hall C(=No.3) on the 3rd floor of New Econ. Building
報告：
Wataru Ohta 太田 亘 (Nagoya University)
An Effect of Time Precedence and Tick Size in Limit Order Markets
Abstract:
This article presents a Markov perfect equilibrium for a dynamic limit order market where traders' strategies depend on the states of the book. For simplicity, I assume that limit orders expire in two periods after their submissions and that there is no asymmetric information among traders. If an exchange enforces times precedence, traders successively undercut the best quote by one tick and undercut it by more than one tick once it reaches a certain level. This quote jump creates a hole in the book. If an exchange does not enforce time precedence, traders may queue at the best quote. The model suggests that enforcing time precedence and a fine tick size encourage traders to compete in price.
日時：
6月10日（火）16:50-18:30
場所：
東京大学経済学研究科棟第3教室（経済学部新棟3階）
at the Lecture Hall C(=No.3) on the 3rd floor of New Econ. Building
報告：
Sougata Poddar (Department of Economics, National University of Singapore)
On Software Piracy   Abstract  PAPER 1  PAPER 2
日時：
6月17日（火）16:50-18:30
場所：
東京大学経済学研究科棟第3教室（経済学部新棟3階）
at the Lecture Hall C(=No.3) on the 3rd floor of New Econ. Building
報告：
Hiroshi Ohashi (University of Tokyo)
Learning by Doing, Export Subsidies,and Industry Growth: Japanese Steel in the 1950s and 60s
Abstract:
The paper examines the Japanese steel industry in the 1950s and 60s to evaluate the role of export subsidy policies. Export subsidies can be instrumental in increasing an industry's cost competitiveness in the presence of learning by doing, a characteristic of production in the steel industry. The proposed approach addresses identification issues found in the literature. Using a dynamic estimation model, this paper identifies a significant learning rate of roughly 20%. It also finds little intra-industry knowledge spillover, an observation that is consistent with the nature of the Japanese employment system at that time. Simulations of the model indicate that the subsidy policy had an insignificant impact on industry growth. The paper provides underlying economic reasons for the simulation results.
日時：
6月24日（火）16:50-18:30
場所：
東京大学経済学研究科棟第3教室（経済学部新棟3階）
at the Lecture Hall C(=No.3) on the 3rd floor of New Econ. Building
報告：
Daisuke Nakajima (Princeton University)
Non-Equivalence Between the First-Price and the Dutch Auctions with non-Expected-Utility Bidders ※印刷に問題が出た場合は当日配布物をお待ち下さい。
Abstract:
This paper investigates the Dutch and the first-price auction, which have traditionally been considered as strategically equivalent. We show that for non-expected-utility preference which exhibits the Allais paradox, there is a systematic dierence and the Dutch auction yields a higher revenue to the seller than the First-price auction.
日時：
7月1日（火）16:50-18:30
場所：
東京大学経済学研究科棟第3教室（経済学部新棟3階）
at the Lecture Hall C(=No.3) on the 3rd floor of New Econ. Building
報告：
Satoru Takahashi (Graduate School, Harvard University)
Monotone Methods for Equilibrium Selection under Perfect Foresight Dynamics (joint with Daisuke Oyama and Josef Hofbauer)
Abstract:
This paper studies equilibrium selection in supermodular games based on a class of perfect foresight dynamics. A normal form game is played repeatedly in a large society of rational agents. There are frictions: Opportunities to revise actions follow independent Poisson processes. Each agent forms his belief about the future evolution of action distribution in the society to take an action that maximizes his expected discounted payoff. A perfect foresight path is defined to be a feasible path of action distribution to which every agent at revision opportunity takes a best response. A Nash equilibrium is said to be absorbing if there exists no perfect foresight path escaping from a neighborhood of this equilibrium; a Nash equilibrium is said to be globally accessible if for each initial distribution, there exists a perfect foresight path converging to this equilibrium. By exploiting the monotone structure of the dynamics, a unique Nash equilibrium that is absorbing and globally accessible for any small degree of friction is identified for certain classes of supermodular games. For games with monotone potentials, the selection of the monotone potential maximizer is obtained. Complete characterizations of absorbing equilibrium and globally accessible equilibrium are given for binary supermodular games. An example demonstrates that unanimity games may have multiple globally accessible equilibria for a small friction.
日時：
7月8日（火）16:50-18:30
場所：
東京大学経済学研究科棟第3教室（経済学部新棟3階）
at the Lecture Hall C(=No.3) on the 3rd floor of New Econ. Building
報告：
Kuniyoshi Saito, 斉藤都美 (Graduate School of Economics, The University of Tokyo）
Testing for Asymmetric Information in Auto Insurance Market: Does Non-Discriminatory Pricing Induce Adverse Selection? Revised Version (December, 2003)
Abstract:
Recent empirical studies in competitive automobile insurance markets show there are no signs of adverse selection nor moral hazard in these markets. However, in the automobile insurance market in Japan, a strict discriminatory pricing reflecting drivers' characteristics has been avoided and its unique market structure made it possible. As a result, insurers have utilized no statistical discrimination by region, sex, or annual mileages, which surely have strong correlation with drivers' risk. In this paper, we ask whether or not such a non-discriminatory pricing policy in insurance market introduces adverse selection and/or moral hazard. Using more than twenty thousand individual data from a non-life insurance company in Japan, we test the correlation between risk and coverage which should be observed under asymmetric information. The result is the same as recent studies in competitive markets: the null of (conditional) independence between risk and coverage is not rejected for both beginners and more experienced drivers. This result is extremely robust in the sense that it holds under several empirical procedures and different definitions of risk and coverage.
Daisuke Tsuruta, 鶴田大輔 (Graduate School of Economics, The University of Tokyo)
Bank Information Monopoly and Trade Credit: Does Only Bank Have Information? - Evidence from Small Business Data in Japan -
Abstract:
Previous studies show that a relationship between a borrower and a bank affects the credit availability to the borrower since it mitigates the problem of information asymmetry. But there is the cost of lending relationship. According to Sharpe (1990), an informed bank can set a higher interest rate since information asymmetry limits competitions between banks. However, even if a borrower has a relationship with only one bank, the cost of lending relationship may not be serious since informed non-financial firms may finance the borrower. The purpose of this study is to investigate empirically whether the cost of lending relationship is serious for small firms. In this paper, I focus on trade credit, which is another method of financing instead of bank loans for borrowers. I examine the following questions: 1) Which firm uses trade credit? 2) Can an informed bank set a higher interest rate to extract rent from a borrower? Can a borrower take credit from other firms when the bank sets a higher interest rate? Using the sample of small firms in Japan, my analysis shows that 1) the less collateral asset a firm possesses, or the higher the growth rate of the firm is, the higher the ratio of account payable is. 2) When the interest rate the bank sets is too severe or is worsened for the borrower, the ratio of account payable increases. This result implies that if the bank offers a high interest rate or raises the interest rate, other non-financial firms can finance the borrower. Hence, the problem of the cost of lending relationship is not very serious.
日時：
7月15日（火）16:50-18:30
場所：
東京大学経済学研究科棟第3教室（経済学部新棟3階）
at the Lecture Hall C(=No.3) on the 3rd floor of New Econ. Building
報告：
Yakov Ben-Haim(Technion - Israel Institute of Technology)
Micro-Economics of Information-Gaps
Abstract:
High reward is better than low reward, but the need for feasibility must temper the aspiration for gain. To achieve this balance we must model and manage our severely deficient information about, and understanding of, the processes we confront. We must also re-evaluate our concepts of rational decision-making. This talk presents a conceptual introduction to the info-gap approach to micro-economic decisions under severe uncertainty.
We begin with a simple example: the info-gap analysis of the home-bias puzzle in financial investment. Conventional utility-maximization theories have failed to explain the overwhelming preference for domestic assets which is widely observed. We examine a decision-model based on satisficing the profit and maximizing the robustness to uncertainty to future returns. We show that, by using an info-gap model of uncertainty, the home bias effect is explained with very low shadow costs, across a wide spectrum of OECD countries. (This work was performed in collaboration with Dr. Karsten Jeske of the Federal Reserve Bank of Atlanta.)
After this brief motivation for info-gap decisions, we consider several fundamental issues in the micro-economics of severely deficient information.
We develop a theory of competitive partial equilibrium in which consumers and firms have severely deficient information about production costs. We use non-probabilistic info-gap models of uncertainty to represent this knowledge-deficiency. The analysis is based on the robustness functions for consumers and for firms, which express the degree of an agent's immunity to uncertainty of the cost functions, in decisions regarding consumption and production. Several propositions disclose trade-offs between robustness to uncertainty and the agent's aspiration for reward. Two additional propositions establish info-gap analogs of the neo-classical results which relate price to marginal cost and to marginal utility at competitive equilibrium. We discuss a Pareto-like efficiency which characterizes info-gap competitive equilibrium, and discuss some welfare implications. We demonstrate a "supply-side" feature of info-gap competitive equilibrium: the aspirations of firms, but not of consumers, directly influence price and aggregate consumption.
We will conclude with a brief mention of the info-gap treatment of consumer demand theory. This analysis preserves the phenomenological features of classical demand theory, without the as-sumptions of rational-choice theory: complete, transitive preferences on the options. The info-gap choice problems of robust satisficing (RSP) and opportune windfalling (OWP) correspond to the traditional problems of expenditure minimization (EMP) and utility maximization (UMP), respec-tively. The consumer choice resulting from the RSP is the analog of the Hicksian demand function, while the solution of the OWP is analogous to the Walrasian demand. Specifically, the RSP-solution is a wealth-compensated demand function which obeys Walras' law and the law of price-demand trade-off.
日時：
7月22日（火）16:50-18:30
場所：
東京大学経済学研究科棟第3教室（経済学部新棟3階）
at the Lecture Hall C(=No.3) on the 3rd floor of New Econ. Building
報告：
Sharon Novak(Kellogg School of Management, Northwestern University / CIRJE)
Complementarity Among Vertical Integration Decisions: Evidence from Automobile Product Development (joint with Scott Stern, Northwestern University)
Abstract:
This paper examines complementarity among vertical integration decisions in automobile product development. Though most research assumes that contracting choices are independent of each other, contracting complementarity may arise when governance choices impact the equilibrium degree of coordination among agents. First, effective coordination may depend on the level of (non-contractible) effort on the part of each agent; contracting complementarity results if coordination efforts are interdependent and vertical integration facilitates a higher level of non-contractible effort. Second, effective coordination may require the disclosure of proprietary trade secrets, and the potential for expropriation through an external supply contract may induce complementarity among vertical integration choices. We provide evidence for complementarity in product development contracting by developing an instrumental variables estimator that distinguishes complementarity from unobserved firm-level factors determining contracting mode. While we interpret our findings cautiously, the results suggest that contracting complementarity may be important in contexts where coordination is important to achieve but difficult to monitor.
日時：
7月23日（水 Wednesday）16:50-18:30
場所：
東京大学経済学研究科棟第3教室（経済学部新棟3階）
at the Lecture Hall C(=No.3) on the 3rd floor of New Econ. Building
報告：
Hideo Owan 大湾秀雄(Olin School of Business, Washington University in St. Louis)
Diversity and Productivity in Teams Seminar Paper  Reference Paper
Abstract:
The popular press often touts workforce demographic (e.g., ethnicity and age) diversity as profit enhancing. For instance, diversity may reduce the firm's communication costs with particular segments of customers and may yield greater team problem solving abilities. On the other hand, diversity also may raise communication costs in teams thereby retarding problem-solving ability and slowing productivity growth. Unfortunately, the effect of team diversity on productivity has not been studied formally and little empirical evidence concerning the impact of team diversity on productivity is found in the literature. This paper formally and empirically explores the impact of diversity in the abilities and demographics of a firm's workforce on the productivity of teams and worker turnover. Our formal model argues that diversity in skill level and ability enhances the team productivity if there is significant mutual learning and collaboration within the team, while demographic diversity is likely to harm productivity by making learning and peer pressure less effective and to increase team-member turnover. To evaluate these propositions we use a novel data from a garment plant that shifted from individual piece rate to group piece rate production over three years. Because we observe individual productivity data, we are able to econometrically distinguish between the impacts of diversity in worker abilities and demographic diversity. Consistent with our formal model, our results indicate that more heterogeneous teams in terms of worker abilities are more productive. Holding the distribution of team ability constant, teams with greater diversity in age are less productive, and those composed only of one ethnicity (Hispanic workers in our case) are more productive, but the findings for team demographics are not robust to alternative specifications of the regression model. Finally, workers on all Hispanic teams are less likely to leave the team, even after accounting for team productivity, indicating some preference for segregation among these workers.
日時：
7月29日（火）16:50-18:30
場所：
東京大学経済学研究科棟第3教室（経済学部新棟3階）
at the Lecture Hall C(=No.3) on the 3rd floor of New Econ. Building
報告：
Naoki Kakita 垣田直樹(Toyama University)
Transboundary Pollution and Trade Policy
Abstract:
This paper examines how transboundary pollution affects non-cooperative tariffs and export subsidy using a two-country intra-industry trade model in which goods are produced by a monopoly firm in each country. It is shown that, if the environmental damage caused by pollution is local (global), on the tariff space the slope of the government reaction function is positive (negative). On the other hand, if the environmental damage caused by pollution is local (global), on the export subsidy space the slope of the government reaction function is negative (positive). Considering the one-way pollution too, this paper compares the Nash with the Stackelberg equilibrium.
日時：
9月2日（火）16:50-18:30
場所：
東京大学経済学研究科棟第１共同研究室（経済学部新棟12階）
at the Conference Room A(=No.1) on the 12th floor of New Econ. Building
報告：
Reiko Aoki (University of Auckland/Hitotsubashi University)
The Utility Requirement and Patentability of Intermediate Reseach (with Sadao Nagaoka)
Abstract:
We explore the consequences of the utility requirement on speed of innovation and welfare. A weak utility requirement means that an intermediate technology with no immediate application or commercial value is patentable. Using a model of two stage innovation with free entry and trade secrecy, we identify cases when patentability is beneficial to society. Although a firm may undertake basic research protected by trade secrecy, patentability is still desirable when spillover is high and innovation costs are high. However, patentability becomes less desirable as basic research costs decrease. We also show that high value of final technology by itself does not favor non-patentability and identify condition when it does.
日時：
9月9日（火）16:50-18:30

!!!場所が変更となりましたのでご注意下さい。ROOM CHANGED !!!

場所：
東京大学経済学研究科棟第2教室（経済学部新棟3階）
at the Lecture Hall B (=No.2) on the 3rd floor of New Econ. Building
報告：
伊藤秀史 Hideshi Itoh(一橋大学商学部)
Moral Hazard and Other-Regarding Preferences
Abstract:
In this paper I attempt to obtain new theoretical insights by combining the standard moral hazard models of principal-agent relationships with theories of other-regarding (inequity averse or status-seeking) preferences. In the benchmark principal-agent model, the principal and the agent are both risk neutral, while the agent is wealth constrained, and hence the basic tradeoff between incentives and rent extraction arises. I show that other-regarding preferences interact with incentives in nontrivial ways. In particular, the principal is in general worse off as the agent cares more about the well-being of the principal. I then extend the analysis to a multi-agent setting. When each agent cares about the well-being of the other agent, either a team contract or a relative performance contract is optimal even though there is no technological externality nor correlation. The extreme team contract is "fair" and more likely to be optimal as actions become mutually observable. However, team contracts are never optimal when the agents are competitive or status-seeking.
日時：
9月16日（火）16:50-18:30
場所：
東京大学経済学研究科棟第3教室（経済学部新棟3階）
at the Lecture Hall C(=No.3) on the 3rd floor of New Econ. Building
報告：
Ryo Ogawa (Graduate School of Economics, University of Tokyo)
Memoryless Contract in Dynamic Moral Hazard with History Dependence
Abstract:
We examine the role of history dependence in a two-period dynamic moral hazard model. The main result is that payments in the optimal long-term contract may not be dependent on the realization of past outcomes, which is a complete contrast to the result in models without history dependence that the optimal long-term contract generally reflects the memory of past outcomes. Sufficient conditions for the result and its interpretations are also discussed.
日時：
9月30日（火）16:50-18:30 ※ 東京大学社会科学研究所プロジェクトセミナーと共催
場所：
東京大学経済学研究科棟第3教室（経済学部新棟3階）
at the Lecture Hall C(=No.3) on the 3rd floor of New Econ. Building
報告：
Chongwoo Choe (Australian Graduate School of Management)
Delegated Contracting and Corporate Hierarchies (joint with In-Uck Park)
Abstract:
In a typical corporate hierarchy, the manager is delegated the authority to make decisions that set directions for the organization, employ subordinates and contract with external suppliers. This paper explains when such delegation of authority is optimal, using a model of a firm with three parties: the principal, the manager and the worker. In centralization with two two-tier hierarchies, the principal designs contracts for both agents. In delegation with a three-tier hierarchy, the principal directly contracts with a delegated agent who, in turn, contracts with the other agent. We identify an environment where the principal can benefit from delegating authority to the manager, but not to the worker. Beneficial delegation arises endogenously when delegation motivates the manager to acquire valuable information, which is used for better decision-making and more efficient incentive provision to the worker. We also show how total surplus is distributed in delegation vis-a-vis centralization, document comparative statics results regarding the benefits of delegation and the distribution of total surplus, and discuss when delegation is more likely to dominate centralization.
日時：
10月7日（火）16:50-18:30
場所：
東京大学経済学研究科棟第3教室（経済学部新棟3階）
at the Lecture Hall C(=No.3) on the 3rd floor of New Econ. Building
報告：
小西秀樹 Hideki Konishi (学習院大学経済学部）
Inter-governmental versus Inter-source Emissions Trading When Firms are Noncompliant
Abstract:
This paper analyzes the relative cost-effectiveness of the inter-governmental versus inter-source system of cross-order emissions trading when polluting firms are noncompliant. A special focus is placed on the presence of enforcement costs and the associated credibility problem of governmental monitoring. It is shown that without inspection commitment, the inter-governmental system is more cost-effective because of the endorsed flexibility in domestic emission taxation, which serves as a commitment device for improving the credibility of extensive monitoring.
日時：
10月14日（火）16:50-18:30
場所：
東京大学経済学研究科棟第3教室（経済学部新棟3階）
at the Lecture Hall C(=No.3) on the 3rd floor of New Econ. Building
報告：
松島　斉 Hitoshi Matsushima (東京大学）
Implementation and Preference for Honesty
Abstract：
We investigate implementation of social choice functions that map states to lotteries, where agents have preferences not only for consequences but also for 'honesty'. We show　that in the complete information environments with three or more agents, every social　choice function is implementable in Nash equilibrium. This is in contrast with the standard　implementation models where agents have preferences only for consequences and no social choice function depending on factors other than agents' preferences is implementable. We show also that in the incomplete information environments with two or more agents, every Bayesian incentive compatible social choice function can be implemented in Bayesian Nash equilibrium by a mechanism that is universal in the sense that it does not depend on the detail of the private signal structure.
日時：
10月21日（火）16:50-18:30
場所：
東京大学経済学研究科棟第3教室（経済学部新棟3階）
at the Lecture Hall C(=No.3) on the 3rd floor of New Econ. Building
報告：
花薗　誠 (京都大学経済研究所）
Collusion, Fluctuating Demand, and Price Rigidity (with Huanxing Yang (University of Pennsylvania))
Abstract：
We study an infinitely repeated Bertrand game in which an i.i.d. demand shock occurs in each period. Each firm receives a private signal about the demand shock at the beginning of each period. At the end of each period, information about the underlying demand shock and the rivals' prices becomes public. A firm's pricing schedule can be either a sorting scheme, in which its price depends on its private signal, or a price-rigidity scheme in which the firm charges the same price regardless of its private signal. We consider the optimal strongly symmetric perfect public equilibrium (SSPPE). The optimal SSPPE consists of a profile of price-rigidity schemes if the accuracy of the private signals is low. Moreover, the lower the variance of the demand shock, the more likely that a price-rigidity scheme is optimal. These results contribute to our understanding of which industries, and under what conditions, should exhibit rigid prices.
日時：
10月28日（火）16:50-18:30 *Presentation in Japanese
場所：
東京大学経済学研究科棟第3教室（経済学部新棟3階）
at the Lecture Hall C(=No.3) on the 3rd floor of New Econ. Building
報告：
浅古泰史 (一橋大学大学院）
The Board of Directors as a Decision Maker and its Optimal Composition
Abstract：
This paper considers the optimal ratio and number of outside directors on the board, assuming the essential function of the board is decision making. And, it demonstrates the difficulties associated with outside directors. We clarify several requirements of an optimal board. First, if the expected profit falls, the optimal ratio of outsiders usually rises. Second, the optimal number of outsiders is determined by the trade-off between an increase in active outsiders and the free-rider problem. Penalties can resolve the moral-hazard problem between outside directors and investors. However, if such penalties increases, recruiting outside directors will be more difficult.
日時：
11月4日（火）15:00-16:30, 16:50-18:30 ***two back to back seminars***
場所：15:00-16:30
東京大学経済学研究科棟第1共同研究室（経済学部新棟12階）
at the Conference Room A (=No.1) on the 12th floor of New Econ. Building
報告：
Quan Wen (Vanderbilt University)
Repeated Games with Asynchronous Moves
Abstract
We study repeated games with asynchronous moves, where not all players may change their actions in every period. Using a state-dependent backward induction, we derive a player's lowest possible perfect equilibrium payoff, called the effective minimax value, in a repeated game. A player's effective minimax value depends on the structure of players' asynchronous moves. We establish an unconventional Folk Theorem: As players become sufficiently patient, any feasible payoff vector in which every player receives more than his effective minimax value can be approximated by a perfect equilibrium in the repeated game. This result implies a number of Folk Theorems and anti-Folk Theorems in hte current repeated game literature.
場所：16:50-18:30
東京大学経済学研究科棟第3教室（経済学部新棟3階）
at the Lecture Hall C(=No.3) on the 3rd floor of New Econ. Building
報告：
川越敏司 (はこだて未来大学システム情報学部）
Fairness とReciprocity の理論 (加藤一彦・山森哲雄と共著）
Abstract：
アマルティア・センの用語法に従えば,行為のもたらす結果のみを用いて社会的状況を評価する立場を帰結主義(consequentialism)という.個人の効用によって社会的状況を評価する立場を厚生主義(welfarism)という.個人効用の総和をもって社会的状況を評価する立場を総和主義(sum-ranking) という.古典的功利主義は,これらの3 つの立場をともに含んでいる.ここで紹介するfairness とreciprocity の理論どれもが,基本的には厚生主義的なものである.また,第1 部で紹介するfairness の理論は帰結主義的あり,かつ総和主義的である.第2 部および第3 部で紹介するstrategic reciprocity の理論は, fairness の理論に見られる帰結主義を乗り越えることで,数々の実験事実をよりよく説明しようとする試みであるといえる.これらの理論はまた, Geanakoplos, Pearce and Stacchetti (1989) の主観的ゲーム(Psychological Games)の理論にもとづき,総和主義的ではない形で他者の効用を考慮に入れる理論となっている.第4 部では素朴なaltruism のモデルなどを取り上げる.従来の経済学・ゲーム理論が利己的動機をもった合理的主体を想定しているのに対して,第4 部までに紹介するいずれのモデルも,主体は合理的だが利他的動機にもとづいて行動する場合があることを前提としている.第5 部では,これらのモデルとは異なり,主体は利己的だが必ずしも合理的ではない行動をとる場合があることを前提としたモデルの例として, McKelvey and Palfrey (1995/1998)の(quantal response equilibrium を紹介するとともに,最尤法により実験データをモデルに当てはめる方法を説明する.
日時：
11月11日（火）16:50-18:30
場所：
東京大学経済学研究科棟第3教室（経済学部新棟3階）
at the Lecture Hall C(=No.3) on the 3rd floor of New Econ. Building
報告：
宇井貴志　（横浜国立大学経済学部）
Incomplete Information Games with Common Multiple Priors (joint with Atsushi Kajii)
Abstract：
We present a model of incomplete information games with common set of priors. Upon arrival of private information, each player "updtes" by the Bayes rule each of priors in this set to construct the set of posteriors consistent iwth the arrived piece of information. Then the player uses a possibly proper subset of this set of priors to form beliefs about the opponents' strategic choices. And finally evaluates his actions by the most pessimistic belief a la Gilboa and Schmeidler (1989). So each player's preferences may exhibit non-linearity in probabilities which can be interpreted as the player's aversion to ambiguity or uncertainty. In this setup, we define a couple of equilibrium concepts, establish existence results for them, and demonstrate by examples how players' views on uncertainty about the environment affect the strategic outcomes.
日時：
11月18日（火）16:50-18:30
場所：
東京大学経済学研究科棟第3教室（経済学部新棟3階）
at the Lecture Hall C(=No.3) on the 3rd floor of New Econ. Building
報告：
Hisahiro Naito 内藤久裕 (ISER, Osaka University 大阪大学社会経済研究所） Revised Version posted on November 18
Neutrality Theorem Revisited: An Empirical Investigation of Public Goods Provision (joint with Ken Yamada)
Abstract：
Households have many economic roles in society. One of such roles is to share household-level public goods that are jointly consumed by members of the household. Several theoretical models have been proposed in the literature: the unitary model, the non-cooperative game theoretical model and the bargaining model. Identifying those models is important due to implications for public policy. The unitary model predicts the amount of household public goods is neutral with respect to income distribution between husband and wife, and the non-cooperative game theoretical model predicts the neutrality of public goods when both the husband and the wife contribute household public goods. Using the Japanese panel data that has information on household expenditures in detail, we examine the relevance of the unitary model and the non-cooperative game theoretical model. Our findings suggest that neither the unitary model nor the game-theoretical model are relevant for the Japanese data.
日時：
11月26日（水）16:50-18:30 ※通常と曜日が異なりますのでご注意下さい。
場所：
東京大学経済学研究科棟第3教室（経済学部新棟3階）
at the Lecture Hall C(=No.3) on the 3rd floor of New Econ. Building
報告：
石川城太 Jota Ishikawa (一橋大学経済学研究科）
Spillover Effects of Trade Policy in the Presence of a Third Country (joint with Hiroshi Mukunoki)
Abstract：
Using a simple monopoly model, we show that the number of markets and the shape of marginal revenue curve are crucial to evaluate trade policies when the marginal cost is not constant. It is shown that the effects of a tariff-change in a three-country model are in contrast with those in a two-country model. The effects also depend on what trade policy the other importing country adopts. When both importing countries simultaneously change their tariffs, the Metzler paradox may arise.
日時：
12月2日（火）16:50-18:30
場所：
東京大学経済学研究科棟第3教室（経済学部新棟3階）
at the Lecture Hall C(=No.3) on the 3rd floor of New Econ. Building
報告：
土居丈朗 Takero Doi (慶應義塾大学経済学部）
A Missing Link in the Decentralization Reform in Japan
Abstract：
In June 2003, the Koizumi administration created the "Trinity Reform Package." In this context, "trinity" means the decentralization reform process that involves three factors: local tax, local allocation tax grant and national government disbursement. There is, however, a missing link in the reform. This is local bond, which is one of major revenue source for local governments. In particular, system of local bond has a very close relationship with local allocation tax system. Local allocation tax grant also covers debt service expenditure at the local level. Hence, the system itself undermines the sound issuance of local bonds. Moreover current local bond system does not result in awareness as debtors. In thispaper, we build a simple theoretical model describing the Japanese local system, and propose a comprehensive decentralization reform including local bond.
日時：
12月9日（火）16:50-18:30
場所：
東京大学経済学研究科棟第3教室（経済学部新棟3階）
at the Lecture Hall C(=No.3) on the 3rd floor of New Econ. Building
報告：
瀧澤弘和 Hirokazu Takizawa (RIETI)
Coordination Costs and the Optimal Partition of a Product Design *RIETI Discussion Paper Series 03-E-014
Abstract：
The purpose of this paper is to analyze the problem of optimally partitioning a design process of a complex product, and to derive several comparative statics results by utilizing the technique developed by Topkis (1998). By partitioning the product design and assigning each sub-design to a team, there are the benefit of having many smaller real options on the one hand, and the cost resulting from an increased incidence of across-team coordination on the other. Furthermore, by endogenizing the across-team coordination costs, our analysis shows that lower cost of within-team coordination induces coarser partitions and higher costs of across-team coordination, i.e. lower level of information and communication technology (ICT) investment. It is argued that these results may explain the reason for the retarded introduction of the ICT by Japanese firms in the 1970s and 1980s as well as the difference of performance between Route 128 and Silicon Valley in the 1990s. It is also argued that our results are consistent with the empirical finding by Brynjolfsson, Maline, Gurbaxani, and Kambil (1994) that ICT leads to decreases in firm size.
日時：
12月11日(木 Thursday) 11:50-13:20 *brownbag seminar, joint with Macroworkshop
場所：
東京大学経済学研究科棟第1共同研究室（経済学部新棟12階）
at the Conference Room A (=No.1) on the 12th floor of New Econ. Building
報告：
Liran Einav (Stanford University)
Not All Rivals Look Alike: Estimating an Equilibrium Model of the Release Date Timing Game
日時：
12月16日（火）16:50-18:30
場所：
東京大学経済学研究科棟第3教室（経済学部新棟3階）
at the Lecture Hall C(=No.3) on the 3rd floor of New Econ. Building
報告：
石黒真吾 Shingo Ishiguro (大阪大学経済学部)
Information Aggregation and Efficiency under Moral Hazard with Externality
Abstract：
In this paper we investigate the principal-multi agent relationship with moral hazard where a risk neutral principal contracts with multiple risk averse agents and technological externality arises among unobservable action choices of agents. Then we show that the principal can find a mechanism which approximately resolves the trade-off between incentives and risk sharing when the number of agents tends to be large enough. We use a simple contract form, called group punishment scheme, which specifies, for each agent, both reward and penalty to be paid depending on whether all agents can pass some statistical test regarding their aggregated performance signals. Moreover, such efficiency result is obtained as a unique equilibrium outcome under the proposed mechanism. Thus the principal uniquely implements the almost full surplus extraction when there exist many agents. We also extend the result to the case that the performance signals are correlated each other.
日時：
1月6日（火）16:50-18:30
場所：
東京大学経済学研究科棟第3教室（経済学部新棟3階）
at the Lecture Hall C(=No.3) on the 3rd floor of New Econ. Building
報告：
花木伸行 (Earth Institute, Columbia University)
Learning Strategy (with Rajiv Sethi, Ido Erev, and Alexander Peterhansl)
Abstract：
Adaptive learning models that have been tested against experimental data typically share two features: (i) initial attractions (or beliefs) are given exogenously, and (ii) learning is based on the performance of stage-game actions rather than repeated game strategies. We develop a model of learning which endogenizes initial attractions and allows for the learning of repeated game strategies. Learning occurs in two phases. In an initial long-run `pre-experimental' phase, we allow players to explore a complete set of repeated game strategies that satisfy a complexity constraint. The limiting attractions from the first phase are then used as initial attractions in the second, short-run phase, which can be tested against experimental data. We find that, relative to existing adaptive models, we are better able to account for the behavior of subjects in environments where fairness and reciprocity appear to play a significant role.
日時：
1月14日 （水 Wednesday） 4:00-5:30pm ***COE distinguished research seminar series***
場所：
東京大学経済学部 新棟地下１階　第1教室
at the Classroom No.1 on the basement floor of New Econ. Building
報告：
速水佑次郎 Yujiro Hayami (FASID-GRIPS)
Waste Pickers and Collectors in Delhi: Poverty and Environment in an Urban Informal Sector (co-authored with A.K. Dikshit and S.N. Mishra)
Abstract:
Waste pickers and collectors constitute the bottom layer of waste recycling in the metropolis of Delhi. Pickers collect waste just by picking them up from public places such as garbage dumps and streets, whereas collectors purchase waste from waste producers such as households and shops for sale to higher-level waste traders. Most pickers have incomes below the poverty line set by the Planning Commission of India, whereas the majority of collectors earn marginally higher than the poverty-line income. The poverty of pickers is not transitory but perpetual as they have no connection to enter the community of collectors and higher-level waste traders within which the community mechanism works effectively to reduce risk and transaction costs. Despite their low economic and social status, pickers and collectors are making important contributions to society. It is found that pickers and collectors are adding more value than their own income to waste producers' income and to the saving of the city government's expenditure for disposing waste. Increased public supports for not only social services but also production services and infrastructure can be justified not only to reduce poverty but also to further their positive contributions to society.
Keywords:
wastes, recycling, poverty, environment, migration, community
日時：
1月19日（月 Monday) 12:00-13:15 *Macroworkshopと共催
場所：
東京大学経済学部 新棟12階　第1共同研究室
at the Conference Room No.1(A) on the 12th floor of New Econ. Building
報告：
Ilhyock Shim (Stanford University)
Dynamic Prudential Regulation: Is Prompt Corrective Action Optimal?
※修士論文報告会（1月13日・14日・20日・27日・28日） 通常と時間・場所が異なりますのでご注意下さい。
※修士論文報告者の方へ※
1月13,14日発表者は9日（金）、1月20日（火）発表者は15日（木）、1月27日発表者は1月22日（木）、1月28日発表者は1月23日（金）のそれぞれ正午（昼12時）までに富井tomii@e.u-tokyo.ac.jp宛てに発表論文のファイルを送るか、センター研究支援室に持参してください。ファイルは形式は何でも結構ですが一番望ましいものはPDFファイルです。web公開した上、当日用の印刷物を用意いたします。発表論文以外にレジュメ等を用意する場合は各自で用意してください。なお、発表論文を期限までに提出しない場合は、各自で20部ほど印刷物を用意して当日持参してください。
1月13日（火） 場所：第１共同研究室（12階）
15:40-16:20　藪崎敬祐 ガソリン価格に対する規制緩和の影響（田渕・八田・松村）
16:20-17:00　竹田英秋　通勤鉄道における需要供給均衡モデルに関する考察（八田・金本・田渕）
17:00-17:40　西口元久　三大都市圏における住宅供給に関する分析（八田・金本・田渕）
17:40-18:20　北野泰樹　The Effects of Asymmetric Natural Resource Endowment on Agglomeration（伊藤元・田渕・金本）
18:20-19:00　片岡哲志　ごみ有料化政策による生活系一般廃棄物への減量効果分析（金本・八田・後藤）

1月14日（水） 場所：第３教室（3階）
17:40-18:20　長岡慎介　Auctions with Endogenous Budget Constraint（神取・神谷・西村）
18:20-19:00　大橋賢裕　A Characterization of Ex Post Implementation（神取・神谷・西村）

1月20日（火） 場所：第１共同研究室（12階）
15:40-16:20　山口和男　Optimal Audit in the Tax Compliance Game（藤原・松井・松村）
16:20-17:00　川森智彦　Legislative Bargaining and Parties' Patience（藤原・松井・松村）
17:00-17:40　柴田　倫　品質のシグナルとしての広告（日本のパソコン市場の実証分析）（三輪・柳川・大橋）
17:40-18:20　鈴木俊平　申告税制の契約理論的分析（柳川・松島・三輪）
18:20-19:00　宮澤信二郎　不完全な金融契約による投資配分のゆがみと厚生損失（柳川・松島・三輪）

1月27日（火） 場所：第１共同研究室（12階）
15:40-16:20　西畑知明　気象条件の変化が経済活動に与える影響（田渕・藤原・後藤）
16:20-17:00　北川　透　都市内の産業間インタラクションと集積の経済性：日本の都市圏における実証研究（金本・田渕・八田）
17:00-17:40　猪野弘明　Waste Disposal and Recycling in the Environment Policy with Expanded Producer Responsibility（藤原・柳川・松村）
17:40-18:20　安田佳史　私的財の公的供給（柳川・松島・三輪）
18:20-19:00　安田　薫　中古市場における取引費用の考察（松村・松井・藤原）

1月28日（水）場所：第３共同研究室（12階）
15:40-16:20　片山俊介　新規住宅着工のタイミングに関する実証分析（八田・金本・大橋）
16:20-17:00　前田　祐　日本の電気事業におけるアヴァーチ・ジョンソン効果に関する実証研究（八田・金本・大橋）
17:00-17:40　田中　領　公共工事が雇用創出と人口移動に及ぼす影響の分析（八田・玄田・井堀）
17:40-18:20　森下哲嗣　マッチングモデルによる貨幣経済の均衡分析（神谷・西村・神取）
18:20-19:00　辻田朋弘　罰則の抑止効果：経済学的アプローチ（三輪・柳川・大橋）
日時：
2月3日（火 Tuesday) 12:00-13:15
場所：
東京大学経済学部 新棟12階　第1共同研究室
at the Conference Room No.1(A) on the 12th floor of New Econ. Building
報告：
Joe Chen (Johns Hopkins University)
The Market Structure of Nasdaq Dealer Markets and Quoting Conventions
日時：
2月5日（木 Thursday) 12:00-13:15
場所：
東京大学経済学部 新棟12階　第2共同研究室
at the Conference Room No.2(B) on the 12th floor of New Econ. Building
報告：
Sam-Ho Lee (University of Pennsylvania)
Early Admission Program: Does It Hurt Efficiency?
日時：
2月6日（金 Friday) 12:00-13:15
場所：
東京大学経済学部 新棟12階　第1共同研究室
at the Conference Room No.1(A) on the 12th floor of New Econ. Building
報告：
Grace Wong (Princeton University)
Has SARS Infected the Property Market? Evidence from Hong Kong
日時：
2月6日 （金 Friday） 4:50-6:30pm ***COE distinguished research seminar series***
場所：
東京大学経済学部 新棟３階　第２教室
at the Classroom No.2 on the 3rd floor of New Econ. Building
報告：
Avner Greif (Department of Economics, Stanford University)
Institutions and Impersonal Exchange: The European Experience
Abstract:
The division of labor is limited by the extent of the market, which, in turn, is limited by the extent of impersonal exchange. Institutions enabling impersonal exchange are thus crucial for advancing the division of labor and economic efficiency. Historically, if exchange began based on personal relationships within relatively small groups, the emergence of the impartial legal system that facilitates impersonal exchange in the contemporary developed economies presents a puzzle. Effective impartial law entails large fix investment and low marginal costs of conducting impersonal exchange. Why was a legal system supporting impersonal exchange established if the volume of impersonal exchange was initially low?
This paper addresses this question by examining the European experience. The transition to impersonal exchange based on a centralized, impartial law was facilitated by the Community Responsibility System (CRS). The CRS enabled exchange characterized by separation between the quid and the quo over time and space that was impersonal, up to one's community affiliation. It built on self-governed communities, intra-community (partial) enforcement institutions, and non-contractual joint communal liability in inter-community disputes that induced communities to care about their collective reputations. The CRS prevailed throughout Europe during the pre-modern period and although it was self-enforcing, it was also a self-undermining. It entailed processes that reduced its economic efficiency and intra-community political viability. The ability to supply centralized, impartial contract enforcement in various regions of Europe, however, was dependent on political development at that particular point.
This analysis touches upon issues central to institutional analysis in general: self-governed communities that fall between the ways in which we model the state and communities; institutions that combine reputational considerations and coercive power; the endogenous elicitation of impartial justice; the importance of the distinction between personal and communal identities; the substitutability between knowing a person's identity or his past actions; and the importance of over-lapping generations' organizations, such as communities, in facilitating inter-organizational impersonal exchange despite each individual's finite life span.
日時：
2月9日（月) 12:00-13:15 ※ Macroworkshopと共催 ※ 日程変更がありましたのでご注意下さい。
場所：
東京大学経済学部 新棟12階　第1共同研究室
at the Conference Room No.1(A) on the 12th floor of New Econ. Building
報告：
Ke Wang (Stanford University)
Multi-Period Corporate Failure Prediction with Stochastic Covariates
日時：
2月10日（火） 16:50-18:30
場所：
東京大学経済学部 新棟12階　第1共同研究室
at the Conference Room No.1(A) on the 12th floor of New Econ. Building
報告：
Yukihiro Nishimura 西村幸浩（Yokohama National University 横浜国立大学経済学部）
Implications of Public Policies under An Incomplete Insurance Market and Second-Best Taxation
Abstract:
This paper extends the analysis of optimal income taxation under uncertainty studied by Cremer and Pestieau (1996, International Tax and Public Finance). We introduce asymmetric information in the insurance market whereby private insurance companies cannot identify the risk probability of the agents, and examine the effect on public policy. We focus on the separating equilibrium of Rothschild and Stiglitz (1976, Quarterly Journal of Economics) and Riley (1979, Econometrica) where the low risk agent is only partially insured, and derive formulae for the optimal income tax rate and the rate of social insurance. This adds two terms to the optimal tax expressions: 1) the effects on the utility and 2) labor supply of the low risk type from relaxing the self-selection constraint in the insurance market. They conflict as in the equity-efficiency conflict in the typical optimal tax formula. We also examine the case of moral hazard.
Key Words:
Adverse Selection, Moral Hazard, Optimal Taxation, Social Insurance
日時：
2月17日（火） 16:50-18:30
場所：
東京大学経済学部 新棟12階　第3共同研究室
at the Conference Room No.3(C) on the 12th floor of New Econ. Building
報告：
Takako Greve グレーヴァ香子（Keio University 慶應義塾大学経済学部）
Possibility and Impossibility of Learning with Limited Behavior Rules (joint with Carsten Krabbe Nielsen, Universita Cattolica, Milan)
Abstract:
We consider boundedly rational learning processes in which players have a priori limited set of behavior rules. A behavior rule is a function from information to a stage-game action, which reflects the available information and one's reasoning about how others act. Commonly used behavior rules include the adaptive rule and the conservative rule (inertia). Sophisticated players may use iterative best responses, called forward-looking behavior rules. The feasible behavior rules set the framework and limitations of learning processes.
We investigate a general relationship between the set of feasible behavior rules and the properties of the long-run outcomes of any learning process restricted to use the feasible behavior rules. From very limited set of behavior rules to increasingly sophisticated ones, robust limit actions are what we call minimal weak-curb sets. In order to converge to a minimal weak-curb set of arbitrary stage game, it is sufficient that the players have one period memory and use one-step different behavior rules. For some classes of games where minimal weak-curb sets coincide with Nash equilibria, we have a global convergence to a Nash equilibrium under very limited set of behavior rules. For other games, however, there is a limit to learning. We show that for any finite set of behavior rules and finite memory length, there is a class of stage games whose unique Nash equilibrium cannot be reached from some initial states. More sophistication of reasoning does not mean better convergence in the sense that the process stays in a smaller set or finds a minimal curb set, which is a set-generalization of Nash equilibrum. The key to finding curb sets is not only the depth of thinking but also the stage game payoff structure. That is, smartness alone cannot find a rational action without the aid of a payoff incentive to explore actions.
日時：
2月27日（金） 11:30-13:00 *Macroworkshopと共催
場所：
東京大学経済学部 新棟12階　第1共同研究室
at the Conference Room No.1(A) on the 12th floor of New Econ. Building
報告：
Toshi Iizuka(Vanderbilt University)
The Effects of Direct-to-Consumer Advertising in the Prescription Drug Markets (joint with Ginger Z. Jin, University of Maryland)
Abstract:
In August 1997, the Food and Drug Administration permitted brand-specific direct-to-consumer (DTC) advertising on electronic medias without "brief summary" of comprehensive risk information. This led to a three-fold growth of DTC advertising expenditure in four year, followed by an intensive debate about their effects on patient and doctor behaviors. This paper examines the effects of DTC advertising of prescription drugs on patient and doctor behaviors, comgining 1994-2000 DTC advertising data with the National Ambulatory Medical Care Survey. We find that, consistent with the poponents' claim, DTC ads increase the number of outpatient drug visits, but have no positive effect on doctors' specific choice within a therapeutic class. This suggests that the effect of DTC advertising is primarily market expanding and DTC advertising is a public good within a therapeutic class. Moreover, the market-expanding effect is much stronger after 1997, explaining the surge of DTC ads after the clarification.
日時： ***COE distinguished research seminar series***
3月1日（月 Monday） 16:50-18:30 *Macroworkshopと共催
場所：
東京大学経済学部 新棟3階　第2教室
at the Lecture Hall No.2(B) on the 3rd floor of New Econ. Building
報告：
Kiminori Matsuyama 松山公紀(Northwestern University)
Credit Traps & Credit Cycles
***COE Frontier Economics Lecture Series, "Bayesian Learning in Games"***
John Nachbar, a leading researcher in the field, delivers two lectures on the recent developments in Bayesian learning theory in games. This is the first of our COE Frontier Economics Lecture Series, which is open to all graduate students and fellow researchers.

日時：
3月19日（金 Friday） 15:00-16:30 *Microworkshopと共催
場所：
東京大学経済学部 新棟3階　第3教室
at the Lecture Hall No.3(C) on the 3rd floor of New Econ. Building
報告：
John Nachbar(Washington University) *Reference paper 1 for March 19 and 22's talks.


日時：
3月22日（月 Monday） 15:00-16:30 *Microworkshopと共催
場所：
東京大学経済学部 新棟3階　第3教室
at the Lecture Hall No.3(C) on the 3rd floor of New Econ. Building
報告：
John Nachbar(Washington University) *Reference paper 2 for March 19 and 22's talks.




日時：
3月23日（火 Tuesday） 16:50-18:30
場所：
東京大学経済学部 新棟3階　第3教室
at the Lecture Hall No.3(C) on the 3rd floor of New Econ. Building
報告：
John Nachbar(Washington Univeristy)
General Equilibrium Comparative Statics