Workshops

2010年4月7日（水　Wednesday） 11:00-12:00 ※　日時にご注意下さい。

Margaret Kyle （Toulouse School of Economics)

Drug Development Before and After TRIPS (joint with Anita M. McGahan) [paper]

We examine the relationship between patent protection for pharmaceuticals and investment in development of new drugs. Patent protection has increased around the world as a consequence of the TRIPS Agreement, which specifies minimum levels of intellectual property protection for members of the World Trade Organization. It is generally argued that patents are critical for pharmaceutical research efforts, and so greater patent protection in developing and least-developed countries might result in greater effort by pharmaceutical firms to develop drugs that are especially needed in those countries. Since patents also have the potential to reduce access to treatments through higher prices, it is imperative to assess whether the benefits of increased incentives have materialized in research on diseases that particularly affect the poor. We find that patent protection is associated with increases in research and development (R&D) effort when adopted in high income countries. However, the introduction of patents in developing countries has not been followed by greater investment. Particularly for diseases that primarily affect the poorest countries, our results suggest that alternative mechanisms for inducing R&D may be more appropriate than patents.

2010年4月7日（水 Wednesday） 16:50-18:30
※金融センター・ワークショップと共催。曜日にご注意下さい。

報告者：Guillaume Plantin （Toulouse School of Economics and CEPR）

Rewarding Trading Skills Without Inducing Gambling (joint with Igor Makarov)

This paper develops a model of active portfolio management in which fund managers may secretly gamble in order to manipulate their reputation and at- tract more funds. We show that such trading strategies may expose investors to severe losses and are more likely to occur when fund managers are impatient, their trading skills are scalable and generate higher pro t per unit of risk. We characterize the optimal contracts that deter this behavior. Our model can ex- plain a number of observed di erences in performance between mutual and hedge fund. In particular, it explains why persistence in returns and net risk-adjusted returns can be higher for hedge funds, and o ers a rationale for the prevalence of high-water mark contracts.

2010年4月13日（火　Tuesday） 16:50-18:30

関口洋平 (Yohei Sekiguchi) （University of Tokyo)

Impossibility of Partitioning Linearly Ordered Alternatives by Aggregating Opinions

We consider the problem of partitioning linearly ordered alternatives: A social planner decides the rule determining how to divides alternatives into indifferent classes which are intervals. We show the impossibility results such that there is no appropriate way of determining the rule by aggregating opinions of members in the society. Formally, any rule satisfying Independent of Irrelevant Alternatives and Non-Imposition is either null or dictatorial.

2010年4月20日（火　Tuesday） 16:50-18:30 　
※Schedule Cancelled/本日の発表は中止となりました。※

大橋弘 (Hiroshi Ohashi) （University of Tokyo)

Assessing the Consequences of a Horizontal Merger and its Remedies in a Dynamic Environment (joint with Satoshi Myojo) [PDF]

This paper estimates a dynamic oligopoly model to assess the economic consequences of a horizontal merger that took place in 1970 to create the second largest global pro- ducer of steel. The paper solves a Markov perfect Nash equilibrium for the model and simulates the welfare e?ects of the horizontal merger. Estimates reveal that the merger enhanced the production e¢ ciency of the merging party by a magnitude of 4.1 %, while the exercise of market power was restrained primarily by the presence of fringe com- petitors. The merger altered the nature of strategic interaction in investment behavior among .rms. Our simulation result also indicates that structural remedies endorsed by the competition authority failed to promote competition.

2010年4月27日（火　Tuesday） 16:50-18:30

佐藤崇 (Takashi Sato) （Toyo University)

A brief introduction to quantum game theory [paper1] [paper2]

In this session, I would like to give a brief introduction to quantum game theory via referring to its history, the basic concepts of quantum mechanics and quantum information, the major formalizations of quantum game, and my co-authored articles on quantum extension of Cournot and Bertrand competition.

2010年5月10日（月　Monday） 12:00-13:30
※日時にご注意下さい。
※　UTIPE Distinguished Research Seminar Seriesと共催

Bruno Strulovici （Northwestern University)

Dynamic Contracting with Moral Hazard and Persistent Private Information (Preliminary)

2010年5月11日（火　Tuesday） 16:50-18:30
※　UTIPE Distinguished Research Seminar Seriesと共催

西村直子 （Shinshu University)

Non-equivalence between the Dutch and the First price auctions with reciprocally spiteful bidders [PDF]

Within the independent private value model, the Dutch descending-bid auction and the first price sealed-bid auction shares the same equilibrium bidding strategy. This is one of the building blocks of the classic revenue equivalence theorem, along with the isomorphism between the English ascending-bid auction and the second price sealed-bid auction. At the same time, however, it is also well known that the winning bids observed in laboratory Dutch auctions are significantly lower than those in first price auctions (see Kagel 1995).

There have been several theoretical attempts to explain the strategic non-equivalence between the Dutch and the first price auctions under the independent private value assumption, including Weber (1982), Chew and Nishimura (2001), and Nakajima (2003). These studies introduce bidders with non-expected utility preferences and show their optimal bidding strategies change as the Dutch clock comes down. While these theories succeed in explaining the non-equivalence, they predict that bidders' optimal bids in the Dutch auction are bounded from below by those in the first price auction if bidders' preferences are consistent with the famous Allais paradox, which is opposite to the experimental results.

This paper explores an alternative explanation for such strategic non-equivalence between Dutch and first price auctions: reciprocal preferences. A disadvantageous bidder with lower value is spiteful in the sense that her utility increases as the earnings of her rival decrease if she loses. If the lower value bidder overbids to shade the higher value bidder's winning payoff, the higher bidder can retaliate by deliberately lose and collect positive losing utility knowing her rival suffering negative payoff. However, once both bidders underbid such that both bidders potentially earn positive winning payoff, it is not fun for the lower value bidder to win with the bid close to her value without responding enough to her rival's underbidding. In order to incorporate such two-way interaction between bidders, we construct a two-bidder, intention-based sequential decision model that shares its sprit with the work by Dufwenberg and Kirchsteiger (2004). We show that equilibrium bids in the Dutch auction are more likely to be lower than those in the first-price auction. This result holds for both complete and incomplete information environment. In addition, our equilibrium bids in the first price auction are higher than those predicted by the conventional risk neutral self-interest agents without referring to risk aversion.

We also present experimental evidence broadly consistent with the predictions of this model. In the complete information environment, some lower value bidders overbid in the both auctions. The higher value bidders tend to wait for the Dutch clock to descend further beyond their corresponding bids in the first price auction so that more bidders with lower value win with negative payoff in the Dutch auction. Average prices in the first price auction are higher than those in the Dutch auction in both complete and incomplete information environment. The fact that we observe such different bidding pattern between two forms of auction even in the complete information environment certainly suggests that the factors other than risk preferences must be the working force in bidders' mind.

This paper is a sequel to Nishimura et al. (2007) which examines the role of reciprocally spiteful bidding behavior in the English ascending-bid auction and the second price sealed-bid auction. Our study theoretically as well as experimentally shows more frequent aggressive spiteful overbidding in the second price auction than in the English auction particularly in the complete information environment where bidders can judge their relative position. Spiteful biddings in experimental second price auctions have recently documented also by Cooper and Fang (2007) and Andreoni et al. (2007). These studies including this paper belong to the line of research just started to examine social preferences in the competitive environment.

2010年5月18日（火　Tuesday） 16:50-18:30
※　UTIPE Distinguished Research Seminar Seriesと共催

Tilman Borgers （University of Michigan)

When Are Signals Complements or Substitutes? (joint with Angel Hernando-Veciana and Daniel Krähmer) [PDF]

The paper introduces a notion of complementarity (substitutability) of two signals which requires that in all decision problems each signal becomes more (less) valuable when the other signal becomes available. We provide a general characterization which relates complementarity and substitutability to a Blackwell comparison of two auxiliary signals. In a setting with a binary state space and binary signals, we nd an explicit characterization that permits an intuitive interpretation of complementarity and substitutability. We demonstrate how these conditions extend to more general settings.

2010年5月25日（火　Tuesday） 16:50-18:30

森田穂高 (Hodaka Morita) （University of New South Wales)

Partial Equity Ownership and Knowledge Transfer (joint with Arghya Ghosh) [paper]

When firms form an alliance, it often involves one firm acquiring an equity stake in its alliance partner. Such an alliance lessens the competition, but induces knowledge transfer within the alliance. This paper explores oligopoly models that capture this important link between partial equity ownership (PEO) and knowledge transfer. We consider an industry consisting of three firms, where firm 1 has superior knowledge that other firms in the industry do not have. Firms 1 and 2 have an option of forming an equity strategic alliance in which firm 1 owns a fraction of firm 2's share. The equilibrium level of PEO is endogenously determined in our model. Previous theoretical models of PEO, in which the levels of PEO are exogenously given, have shown that PEO arrangements would decrease welfare by reducing the degree of competition in the industry. We demonstrate that endogenously determined levels of PEO can increase welfare under a range of parameterizations. Our analysis indicates that there are three relevant policy interventions (prohibit PEO, partially permit PEO, or permit PEO) for antitrust authorities to maximize welfare, and shows that any one of the three can be optimal depending on parameterizations.

2010年5月27日（木　Thursday） 12:00-13:00
※日時にご注意下さい。
※　UTIPE Distinguished Research Seminar Seriesと共催

小島武仁 (Fuhito Kojima) （Stanford University)

Improving Efficiency in Matching Markets with Regional Caps: The Case of the Japan Residency Matching Program (joint with Yuichiro Kamada)

Geographical distribution of medical doctors is a hotly debated issue in the medical community and in public policy on health care. One of the problems is that many hospitals, especially those in rural areas, do not attract sufficient numbers of medical residents to meet their demands. Previous literature on stable matching suggests that a solution is elusive, as the rural hospital theorem (Roth 1986) implies that any hospital that fails to fill all its positions in one stable matching is matched to an identical set of doctors in all stable matchings. An implication of this result is that a hospital that cannot attract enough residents under one stable matching mechanism cannot increase the number of assigned residents no matter what other stable mechanism is used.

The shortage of residents in rural hospitals is pronounced in Japan, where the deferred acceptance algorithm (Gale and Shapley 1962) has placed over 8,000 residents to about 1,000 doctors each year. In an attempt to increase the placement of residents to rural hospitals, Japanese government recently introduced "regional caps" which, for each of 47 prefectures that partition the country, restrict the total number of students matched within the prefecture.

This paper shows that the current mechanism with regional caps may result in avoidable inefficiency and instability and proposes a mechanism that improves efficiency and generates stable matchings while meeting the regional caps.

More specifically, we first introduce concepts of stability and constrained efficiency that take regional caps into account. We observe that the current Japanese mechanism does not always produce a stable or constrained efficient matching. We present an algorithm that finds a stable and constrained efficient matching. We show that the mechanism is (group) strategy-proof for doctors. These results suggest a potentially superior mechanism than the current one when the government needs to achieve certain distributional goals.

We also find that the set of stable matchings exhibit structural properties different from those in the standard matching problems. Firstly, there does not necessarily exist a doctor-optimal matching (matching unanimously preferred by all doctors). Second, different stable matchings can have different sets of hospitals with vacant positions, implying that the rural hospital theorem fails in our context. Thus there may be room for government to select a particular stable matching based on its welfare and distributional goals.

2010年6月1日（火　Tuesday） 16:50-18:30

山口慎太郎 (Shintaro Yamaguchi) （McMaster University)

Tasks and Heterogeneous Human Capital [paper]

This paper constructs and estimates a structural life-cycle model of occupational choice and heterogeneous human capital formation using occupational task measurements from the Dictionary of Occupational Titles. While the task measurements are usually used as a skill proxy, this paper clearly distinguishes tasks and skills using the Roy model framework. The key feature of the model is that it conceives of an occupation as a bundle of tasks and allows for heterogeneous returns to skills across occupations according to their tasks, departs from other Roy-type models in which occupations are treated as distinct categories. The proposed approach has advantages in that it can accommodate many occupations without computational burden and provides a clear interpretation as to how and why skills are differently rewarded across different occupations. The model is estimated by the Kalman filter using the male sample from the NLSY79. The empirical results indicate that both cognitive and motor skills account for a considerable amount of cross-sectional wage variation. I also find that cognitive skills grow over careers and are the main source of wage growth; this pattern is particularly pronounced for the highly educated. In contrast, motor skills grow and contribute to wage growth substantially for high school dropouts only.

2010年6月15日（火　Tuesday） 16:50-18:30

坂原樹麗 (Kiri Sakahara) （University of Tokyo)

Cognition and Choice (joint with Takashi Sato)

We propose a model of cognition by which agent's choice behaviors are determined. To understand some sort of choice behaviors, it is crucial to model agent's cognition. By modeling individual cognition, we provide a comprehensive view of some peculiar form of choice behaviors. Notations and terminology of channel theory and category theory are introduced to build up our framework.

2010年6月22日（火　Tuesday） 16:50-18:30 ※　UTIPE Distinguished Research Seminar Series、Macroworkshopと共催。

清滝信宏 (Nobuhiro Kiyotaki)(Princeton University)

Financial Intermediation and Credit Policy in Business Cycle Analysis [PDF] [slides]

We develop a canonical framework to think about credit market frictions and aggregate economic activity in the context of the current crisis. We use the framework to address two issues in particular: first, how disruptions in financial intermediation can induce a crisis that affects real activity; and second, how various credit market interventions by the central bank and the Treasury of the type we have seen recently, might work to mitigate the crisis. We make use of earlier literature to develop our framework and characterize how very recent literature is incorporating insights from the crisis.

2010年6月29日（火　Tuesday） 16:50-18:30

グレーヴァ香子 (Takako Fujiwara-Greve )(Keio University)
*発表者が変更致しました。

On the co-existence of cooperation and myopia in Voluntarily Separable Repeated Prisoner's Dilemma (Co-authored with Masahiro Okuno-Fujiwara and Nobue Suzuki)

In incomplete information models with rational and myopic players, the existence of myopic players is usually taken for granted. Such diversity could alternatively be interpreted as a strategic equilibrium phenomenon. In our repeated Prisoner's Dilemma model with voluntary separation, there is an equilibrium in which simple cooperative strategy and myopic strategy coexist. This equilibrium can be stable under social norms or when there is a complexity cost.

2010年7月5日（月　Monday） 12:00-13:00
※日時・会場にご注意下さい。
※Empirical Micro Brown-Bag Lunch Seminar、UTIPE Distinguished Research Seminar Seriesと共催

Tat Y. Chan　（Washington University in St. Louis）

Using Expectations Data to Infer Managerial Objectives and Choices (joint with Barton H. Hamilton and Christopher Makler) [PDF]

We develop a theory-driven empirical framework to analyze managerial decision-making that incorporates subjective expectations data. We apply the model to examine the advertising decisions of the marketing manager of a large university performing arts center who reports her demand forecasts as part of the annual budgeting process. We recover parameters of the manager's utility function and assess the sensitivity of estimated preferences to alternative assumptions regarding her expectations. The results from our structural demand model of ticket sales show that the manager is overoptimistic about the appeal of avant-garde art and advertising effectiveness, although her belief concerning the price elasticity of demand is unbiased. Estimates of managerial utility parameters are sensitive to the specification of expectations: Allowing for biased expectations, the manager exhibits strong preference for avant-garde performances, which is consistent with the mission of the performing arts center. Imposing rational expectations reverses the sign of this key behavioral parameter and implies the manager has distaste for avant-garde art. The results also suggest that the manager attempts to manipulate advertising so that final sales coincide with her ex ante forecast, imposing an agency cost on the performing arts center. Keywords: subjective expectations, biased beliefs, structural

2010年7月6日（火　Tuesday） 16:50-18:30 　
※UTIPE Distinguished Research Seminar Seriesと共催

萱場豊 (Yutaka Kayaba)　（California Institute of Technology）

Nonparametric Learning Rules from Bandit Experiments:The Eyes have it! (joint with Yingyao Hu and Matt Shum) [PDF]

We estimate nonparametric learning rules using data from dynamic two-armed bandit (probabilistic reversal learning) experiments, supplemented with auxiliary measures of subjects' beliefs, in the form of their eye-movements during the learning experiment. We apply recent econometric developments in the estimation of dynamic models. The estimated choice probabilities and learning rules from our nonparametric models have some distinctive features; notably that subjects tend to update in a non-smooth manner following positive "exploitative" choices (those made in accordance with current beliefs). Simulation results show that the beliefs implied by the nonparametric learning rules are more similar to those from a reinforcement learning model, than a Bayesian learning model.

2010年7月13日（火　Tuesday） 16:50-18:30
※UTIPE Distinguished Research Seminar Seriesと共催

山本裕一 (Yuichi Yamamoto)　（Harvard University）

Individual Learning, Dynamic Coordination, and Belief-Free Equilibria

This paper studies two-player repeated games with private monitoring where the state of the world chosen by Nature influences the payoff functions and the monitoring structure. It introduces a tractable subset of sequential equilibria, called belief-free ex-post equilibria (BFXE), and characterizes the limit set of BFXE payoffs as the discount factor converges to one. Under mild identifiability conditions, the limit equilibrium payoff set is isomorphic to the set of maps from states to belief-free equilibrium payoffs for the corresponding known-state game; that is, there are BFXE in which the payoffs are approximately the same as if players learn the true state and play a belief-free equilibrium for that state. Moreover, when the signal distribution is weakly conditionally independent, a larger payoff set can be achieved using a variant of BFXE.

2010年7月20日（火　Tuesday） 16:50-18:30
※UTIPE Distinguished Research Seminar Seriesと共催

中田啓之 (Hiroyuki Nakata)　（University of Essex）

Entropy Characterisation of Insurance Demand: Theory and Evidence (joint with Yasuyuki Sawada and Mari Tanaka) [PDF]

This paper characterises the insurance demand in terms of the entropy of the underlying probability distribution for losses. A characterisation of this nature provides the prediction that insurance for large losses with small probabilities tends to be purchased less frequently than insurance for moderate losses with higher probabilities, without deviating from the standard expected utility framework. The predictions of the theoretical model are tested empirically using household data collected in Vietnam.

2010年7月28日（水 Wednesday） 16:15-17:30
※UTIPE Frontier Economic Lecture Seriesと共催　※ 日時にご注意下さい。

小島武仁 (Fuhito Kojima)　（Stanford University）

Topics in Matching and Market Design II [PDF]

2010年9月22日（水　Wednesday） 16:30-18:00 ※日時にご注意下さい。

Tobias Kretschmer （University of Munich)

Backward Compatibility to Sustain Market Dominance (with Jörg Claussen and Thomas Spengler) [PDF]

The introduction of a new product generation forces incumbents in network industries to rebuild their installed base to maintain an advantage over potential entrants. We study if backward compatibility can help moderate this process of rebuilding an installed base. Using a structural model of the US market for handheld game consoles, we show that backward compatibility lets incumbents transfer network effects from the old generation to the new to some extent but that it also reduces supply of new software. We also find that backward compatibility matters most shortly after the introduction of a new generation. Finally, we examine the tradeoff between technological progress and backward compatibility and find that backward compatibility matters less if there is a large technological leap between two generations. We subsequently use our results to assess the role of backward compatibility as a strategy to sustain a dominant market position.

2010年10月13日（水　Wednesday） 16:50-18:30 ※曜日にご注意下さい。

末廣英生 (Hideo Suehiro) （Kobe University)

Experiments on the Emergence of Leadership in Teams (joint with Koji Abe and Hajime Kobayashi) [PDF]

We study experimentally the emergence of leadership through endogenously formed leader-follower relationships in team production under asymmetric information. In a treatment that theoretically admits leadership, we observed that leadership emerged in a pattern of a particular sequential equilibrium: a subject with a higher expectation of team productivity leads, and one with a lower expectation follows. In a control treatment in which incompleteness of information is removed and one in which payoffs are changed to incorporate a prisoner's dilemma situation, leadership did not emerge. The results support the endogenous signaling theory of leadership in teams proposed by Kobayashi and Suehiro (2005, 2008).

2010年10月19日（火　Tuesday） 16:50-18:30

Stephen Morris （Princeton University)

"Interdependent Preferences and Strategic Distinguishability" (joint with Dirk Bergemann and Satoru Takahashi) [paper]

2010年10月26日（火　Tuesday） 16:50-18:30

Juuso Välimäki (Aalto University School of Economics)

Private and Social Learning in Games of Timing (joint with Pauli Murto) [PDF]

We analyze information aggregation in a stopping game with uncertain payoffs that are correlated across players. Players learn from their own private experiences as well as by observing the actions of other players. We give a full characterization of the symmetric mixed strategy equilibrium, and show that information aggregates in randomly occurring exit waves. Observational learning induces the players to stay in the game longer. The equilibria display aggregate randomness even for large numbers of players.

2010年11月2日（火　Tuesday） 16:50-18:30

国本 隆 (Takashi Kunimoto) （Hitotsubashi University)

A New Necessary Condition for Implementation in Iteratively Undominated Strategies

Implementation in iteratively　undominated strategies relies on permissive　conditions. For the sufficiency results available, although　authors succeed in constructing finite implementing mechanisms, they　have relied on assumptions that amount to quasilinear preferences on　a numeraire. We uncover a new necessary condition for implementation　by mechanisms that satisfy the "best element property" where for each agent, there exist a strategy profile that gives him the highest payoff in the mechanism.　This class includes finite and regular mechanisms. Thus, we conclude　that either quasilinearity-like assumptions cannot be completely dispensed with　or some mechanisms that do not satisfy the best element property must be employed. We term the　condition "restricted deception-proofness."　It requires that, in　environments with identical preferences, the social choice function be immune to all deceptions, making it then stronger than incentive compatibility. In some environments the conditions for　(exact or approximate) implementation by mechanisms satisfying the best element property are more restrictive than previously thought.

2010年11月9日（火　Tuesday） 16:50-18:30

尾山大輔(Daisuke Oyama) （University of Tokyo)

Sampling Best Response Dynamics and Deterministic Equilibrium Selection (joint with William H. Sandholm and Olivier Tercieux)

2010年11月16日（火　Tuesday） 16:50-18:30

Hamid Sabourian （University of Cambridge）

Repeated Implementation [PDF1] [PDF2]

[PDF1]
This paper examines repeated implementation of a social choice function (SCF) with in nitely-lived agents whose preferences are determined randomly in each period. An SCF is repeated-implementable in (Bayesian) Nash equilibrium if there exists a sequence of (possibly history-dependent) mechanisms such that (i) its equilibrium set is non-empty and (ii) every equilibrium outcome corresponds to the desired social choice at every possible history of past play and realizations of uncertainty. We first show, with minor qualifications, that in the complete information environment an SCF is repeated-implementable if and only if it is efficient. We then extend this result to the incomplete information setup. In particular, it is shown that in this case efficiency is sufficient to ensure the characterization part of repeated implementation. For the existence part, incentive compatibility is sufficient but not necessary. In the case of interdependent values, existence can also be established with an intuitive condition stipulating that deviations can be detected by at least one agent other than the deviator. Our incomplete information analysis can be extended to incorporate the notion of ex post equilibrium.

2010年11月30日（火　Tuesday） 16:50-18:30

Abu Shonchoy （IDE-JETRO）

Seasonal Migration and Micro-credit in the Lean Period: Evidence from Northwest Bangladesh [PDF]

Temporary seasonal migration is an issue which is largely ignored in the standard ruralurban migration literature. Seasonal migration due to agricultural downturns is a common phenomenon in developing countries. Using primary data from a cross-sectional household survey from the northwest part of Bangladesh, this study quantifies the factors that influence such migration decisions. Among other results, we find that network effects play a significant role influencing the migration decision. Seasonal migration is a natural choice for individual suffering periodic hardship, however the strict weekly loan repayment rules of Micro-credit can have adverse effect on this process, reducing the ability of borrowers to react to a shock. Our result suggest that poor individuals prefer the option of not accessing the the Micro-credit and opt for temporal seasonal migration during the lean period. The results have numerous potential policy implications, including the design of typical micro-credit schemes.

2010年12月7日（火　Tuesday） 16:50-18:30

Yi-Chun Chen (National University of Singapore)

A structure theorem for rationalizability in dynamic games [paper]

We prove the structure theorem for rationalizability due to (Weinstein, J, Yildiz, M, 2007. A structure theorem for rationalizability with application to robust prediction of refinements. Econometrica 75, 365-400) in any finite extensive-form game with perfect recall and suitably rich payoff parameters. Consequently, in these games no refinements of rationalizability are robust in the sense proposed by Weinstein and Yildiz. To obtain this result, we first observe that for the structure theorem it is both necessary and sufficient that every rationalizable action is the unique rationalizable action for some Harsanyi type, and then demonstrate that the condition is satisfied whenever the payoff parameters are sufficiently rich.

2010年12月14日（火　Tuesday） 16:50-18:30

飯塚敏晃 (Toshiaki　Iizuka) （University of Tokyo)

Doctor-Patient Agency Relationship and Diffusion of Generic Pharmaceuticals

This paper explores the role of doctor-patient agency relationship in the diffusion of generic pharmaceuticals. Exploiting rich micro-panel data, I estimate dynamic panel-data models that explicitly account for doctor financial incentives, patient costs, state dependence, and unobserved heterogeneity. I find that doctors respond to financial incentives, i.e., markup differentials between generics and brand names, but often fail to internalize patient costs, indicating that doctors are imperfect agents for their patients. Additionally, state dependence and heterogeneous preferences strongly affected generics substitution. Policy makers may target these factors to improve static efficiency but some potential drawbacks of so doing are also discussed.

2010年12月15日（水　Wednesday） 12:00-13:30 ※日時と会場にご注意下さい。

Oleg Itskhoki (Princeton University)

Labor Market Rigidities, Trade and Unemployment (joint with Elhanan Helpman) [paper1] [paper2]

[paper1]
We study a two-country, two-sector model of international trade in which one sector produces homogeneous products and the other produces differentiated products. Both sectors are subjected to search and matching frictions in the labour market and wage bargaining. As a result, some of the workers searching for jobs end up being unemployed. Countries are similar except for frictions in their labour markets, such as efficiency of matching and costs of posting vacancies, which can vary across the sectors. The differentiated-product industry has firm heterogeneity and monopolistic competition. We study the interaction of labour market rigidities and trade impediments in shaping welfare, trade flows, productivity, and unemployment. We show that both countries gain from trade. A country with relatively lower frictions in the differentiated-product industry exports differentiated products on net. A country benefits from lowering frictions in its differentiated sector's labour market, but this harms the country's trade partner. Alternatively, a simultaneous, proportional lowering of labour market frictions in the differentiated sectors of both countries benefits both of them. The opening to trade raises a country's rate of unemployment if its relative labour market frictions in the differentiated sector are low, and it reduces the rate of unemployment if its relative labour market frictions in the differentiated sector are high. Cross-country differences in rates of unemployment exhibit rich patterns. In particular, lower labour market frictions do not ensure lower unemployment, and unemployment and welfare can both rise in response to falling labour market frictions and falling trade costs.
[paper2]
This paper reviews a new framework for analyzing the interrelationship between inequality, unemployment, labor market frictions, and foreign trade. This framework emphasizes firm heterogeneity and search and matching frictions in labor markets. It implies that the opening of trade may raise inequality and unemployment, but always raises welfare. Unilateral reductions in labor market frictions increase a country's welfare, can raise or reduce its unemployment rate, yet always hurt the country's trade partner. Unemployment benefits can alleviate the distortions in a country's labor market in some cases but not in others, but they can never implement the constrained Pareto optimal allocation. We characterize the set of optimal policies, which require interventions in product and labor markets.

2010年12月15日（水　Wednesday） 16:50-18:30 ※曜日にご注意下さい。

西村幸浩 (Yukihiro Nishimura) （Osaka University）

Strategic Voting on Environmental Policy Making: The Case for "Political Race to the Top'' (joint with Kimiko Terai) [PDF]

This paper explores the outcome of the noncooperative environmental decision-making under transnational externalities when the national policies are chosen by the elected politicians. Specifically, we re-examine the extent of a voter's incentives for supporting politicians who are less green than she is, a phenomenon called ``political race to the bottom''. The median voter (principal) strategically appoints his delegate (agent) who independently decides the level of environmental investments (as inputs for the global public good) which generate transnational benefits. The new feature of our model is the introduction of complementarity between public inputs, while previous studies supposed perfect substitution. Our analysis derives some new results. The extent of ``political race to the bottom" diminishes as public inputs become more complementary, and if its degree exceeds a certain point, ``political race to the top" emerges, without supposing effects of other factors including international trade. We further examine the case with perfect substitution. Equilibrium is in fact asymmetric. Although one of the elected politicians pays no attention to the environment, the other country results in self-representation.

2010年12月21日（火　Tuesday） 16:50-18:30

宇井貴志 (Takashi Ui) (Yokohama National University）

Normal Form Games with Self-Control Preferences (joint with Norio Takeoka)

The majority of self-control models have been considered in the context of single-person decision making. However, one's propensity to resist temptation may well depend on others' behavior, as observed in smoking, overeating, and overspending behavior. This paper introduces a new class of normal form games in which players have self-control preferences (Gul and Pesendorfer, 2001) and player's ability to resist temptation depends on the other players' actions. We propose an equilibrium concept and establish the existence of equilibria. In addition, we discuss how strategic interaction matters in games with self-control preferences by examples such as consumption-savings decisions under bandwagon effects.

2011年1月11日（火　Tuesday） 16:50-18:30 *都市経済ワークショップと共催

Marcus Berliant (Washington University）

Dynamic Political Agency with Adverse Selection and Moral Hazard [PDF]

We define a general model of electoral accountability in which an electorate chooses between an incumbent and a challenger in an infinite sequence of elections. We assume that politician types are private information and that the actions of an officeholder are unobserved by the electorate, so that adverse selection and moral hazard are both present. We establish existence of a perfect Bayesian equilibrium in pure strategies such that voters and politicians condition on the past only through the voters' beliefs regarding the type of the current officeholder, i.e., the equilibrium is "belief-stationary."

2011年2月15日（火　Tuesday） 16:50-18:30

浅古泰史（Yasushi Asako）(Bank of Japan）

Campaign Promises as an Imperfect Signal: The Electoral Advantages of being an Extreme Candidate [PDF]

This paper develops a political competition model in which campaign platforms are partially binding. A candidate who implements a policy that differs from his/her platform must pay a cost of betrayal that increases with the size of the discrepancy. I also assume that voters are uncertain about candidate preferences for policies. If voters believe that a candidate is likely to be extreme, there exists a semiseparating equilibrium: an extreme candidate imitates a moderate candidate with some probability, and with the remaining probability, he approaches the median policy. Although an extreme candidate will implement a more extreme policy than a moderate candidate regardless of imitation or approach, partial pooling ensures that voters prefer an extreme candidate who does not pretend to be moderate over an uncertain candidate who announces a moderate platform. As a result, a moderate candidate never has a higher probability of winning than an extreme one.

2011年2月28日（月　Monday） 12:00-13:15
※　日時にご注意下さい。　
※ Macroworkshop と共催

大垣昌夫（Masao Ogaki) (Keio University）

Cultures, Worldviews, and Intergenerational Altruism (joint with Kohei Kubota, Charles Yuji Horioka, Akiko Kamesaka, and Fumio Ohtake)

This presents empirical evidence concerning effects of cultural differences on parents' attitudes toward children from unique U.S. and Japanese survey data. These data sets have been collected by Osaka University, and contain questions concerning worldviews and religions, hypothetical questions about parental behavior, and questions about socioeconomic variables. The data show that U.S. parents tend to be tougher than Japanese parents toward young children. Our empirical evidence indicates that people who are confident about issues related to worldviews tend to show tough attitudes toward their children. Our evidence also suggests that contents of worldview beliefs held by parents affect parent's attitudes toward children. Because U.S. parents are much more confident than Japanese parents in worldview issues, this cultural difference helps explain why U.S. parents are much tougher than Japanese.

2011年3月1日（火　Tuesday） 16:50-18:30

田中知美（Tomomi Tanaka) (Arizona State University）

Exchange Economies with Indivisibilities (joint with Marcus Berliant)

This paper studies a general exchange economy with indivisibilities where agents can consume many indivisible commodities, have quasi-linear utility functions, and face budget constraints. We provide a necessary and sufficient condition on primitives that will ensure the existence of competitive equilibrium. This condition says for each agent a bundle can be separated from its upper contour set by a hyperplane. We demonstrate how our assumption is weaker than the gross substitutes condition, originally introduced by Kelso and Crawford for a two-sided matching game.

2011年3月23日（水　Wednesday）16:00-17:30
※下記のセミナーは中止となりました。

Jean-Etienne de Bettignies (Queen's University）

Product Market Competition and Managerial Employment Choices [Abstract]

2011年3月28日（月 Monday）16:50-18:30
※下記のセミナーは中止となりました。

Shouyong Shi (University of Toronto）

TBA

※ 2011年1-2月　修士論文報告会 Master's Thesis Presentations ※

１．下記の予定は変更の可能性もありますのでご注意下さい

（Please note that the schedule below might be changed)。

２．発表は基本的に日本語で行われます

（Presentations are basically in Japanese)。

配布資料の印刷をご希望の方は、下記の期日までにセンター研究支援室の田中(kimiko[at mark]e.u-tokyo.ac.jp)まで発表論文のファイルを送るか、ハードコピーをセンター研究支援室（経済学研究科 学術交流棟（小島ホール） ６階）までご持参下さい。提出されたファイルはすぐに印刷にまわしてしまいますので、その後の差し替えがないよう、最終稿を１度だけ提出してください。 期限内に届いたものについては当日配布用印刷物を用意いたしますが、間に合わない場合やその後の差し替えについては、当日ご自分で１５部ほどコピーをご持参下さい。期限内に提出されなかった場合は、印刷を受け付けられませんのでご注意ください。

※　ミクロ経済学ワークショップを履修しているが、スケジュールの都合で修士論 文の発表がマクロ経済学ワークショップで行われる学生は、特例でミクロ経済学ワーク ショップで発表したものとみなし、ミクロ経済学ワークショップの単位を認定し ます。

※　印刷物は会場に届けられます。

※　パソコン・ポインターはセミナー室ロッカー内の機器をご使用のうえ、設置・片づけは最初と最後の発表者が各自で行って下さい。（プロジェクターは会場に備え付けられています。）

発表論文提出期限：

1月12日（水）発表者＝1月11日（火）朝9:00（必着）まで

1月18日（火）発表者＝1月17日（月）朝9:00（必着）まで

1月19日（水）発表者＝1月18日（火）朝9:00（必着）まで

1月25日（火）発表者＝1月24日（月）朝9:00（必着）まで

2月 1日（火）発表者＝1月31日（月）朝9:00（必着）まで

2011年1月12日（水　Wednesday）16:50-17:30

塚原輝

Two-Sided Marketsにおけるプラットフォームデザイン

2011年1月12日（水　Wednesday）17:30-18:10

森田公之

Information and Uncertainty in Organization

2011年1月12日（水　Wednesday）18:10-18:50

大宮俊吾

Dissent and Authority in Organizations

2011年1月12日（水　Wednesday）18:50-19:30

今江荘人

local matching rule とuniform matching ruleに基づく、企業の国際的なマッチング問題

2011年1月18日（火　Tuesday）16:50-17:30

塚田憲史

Exchange economy on the network

2011年1月18日（火　Tuesday）17:30-18:10

飯島良太

Learning Type Distribution in Search and Matching

2011年1月18日（火　Tuesday）18:10-18:50

久保田荘

Money, Price Posting and Indeterminacy

2011年1月18日（火　Tuesday）18:50-19:30

小西啓吾

Monetary Search and Knightian Uncertainty

2011年1月19日（水　Wednesday）16:50-17:30

金澤匡剛

動画サイトのCD売上へ与える影響

2011年1月19日（水　Wednesday）17:30-18:10

福田つばさ

企業の資本配分と組織形態：分権 vs. 集権 vs. ヒエラルキー

2011年1月19日（水　Wednesday）18:10-18:50

磯野太佑

金融保証におけるシャドー格付の役割

2011年1月19日（水　Wednesday）18:50-19:30

成田悠輔

A Minimalist Approach to Market Design Problems

2011年1月25日（火　Tuesday）16:50-17:30

小林広和

Stability in competition with mail-order business

2011年1月25日（火　Tuesday）17:30-18:10

白田恭平

産業の多様性が地域の生産性に与える影響

2011年1月25日（火　Tuesday）18:10-18:50

山崎潤一

Why do not young people use mosquito nets? ; Difference-in-Difference approach using the discontinuous free nets distributing in Madagascar, 2009

2011年2月1日（火　Tuesday）16:50-17:30

笹井章弘

Productivity and Decision Making of Multinational Enterprises

2011年2月1日（火　Tuesday）17:30-18:10

報告中止となりましたのでご注意下さい。

2011年2月1日（火　Tuesday）18:10-18:50

菊池雄太

Academic Environment and Research Creativity : Evidence from the Institutional Change of the Japanese University