[下载]牛津06书《重复博弈与声誉：长期关系》（Repeated Games and Reputations）

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收藏 2007-10-10

Repeated Games and Reputations: Long-Run Relationships 
by <a href="http://www.amazon.com/exec/obidos/search-handle-url/105-1152057-5208416?%5Fencoding=UTF8&amp;search-type=ss&amp;index=books&amp;field-author=George%20J.%20Mailath" target="_blank" >George J. Mailath</A> (Author), <a href="http://www.amazon.com/exec/obidos/search-handle-url/105-1152057-5208416?%5Fencoding=UTF8&amp;search-type=ss&amp;index=books&amp;field-author=Larry%20Samuelson" target="_blank" >Larry Samuelson</A> (Author) 
<LI>Hardcover: 672 pages 
<LI>Publisher: Oxford University Press, USA (September 1, 2006) 
<LI>Language: English </LI>
<LI>Review "Repeated Games is comprehensive, self-contained, and extremely clear, with proofs that not infrequently improve on the originals. The book is an ideal text for part or all of a second graduate class in game theory, and will be a valuable aid for any student of the field."--Drew Fudenberg, Professor of Economics, Harvard University "George Mailath and Larry Samuelson have written a landmark book in game theory, which takes stock of decades of research on repeated games and dynamic games more generally. The book not only provides an insightful synthesis of the extensive literatures relating to folk theorems, reputation, and play under a variety of information and monitoring structures; but perhaps more importantly it provides some original proofs that shed new light on some of the central results in these areas. This book will be an invaluable resource for researchers in the area, and should also quickly become a standard reading for advanced graduate students."--Matthew O. Jackson, Edie and Lew Wasserman Professor of Economics, California Institute of Technology "The study of repeated games has been one of the most fruitful and important developments in economic theory in the last thirty years. In this beautifully lucid book, George Mailath and Larry Samuelson--two leading researchers in the field--lay out the classic results in detail and also bring the reader up to date with the latest findings."--Eric S. Maskin, A.O. Hirschman Professor of Social Science, Institute for Advanced Study "The theory of reputations in repeated games has become one of the most important areas of research in economic theory, because it offers essential insights into the foundations of economic and political institutions. The past decade has seen great progress in this area, especially in the study of games with imperfect private monitoring. George Mailath and Larry Samuelson have been active leaders in this research, and here they systematically lay out the state of the art. This book will be an important text and reference for years to come."--Roger Myerson, University of Chicago "Theorists use repeated games to understand self-enforcing contracts, and to explore the power of reputation formation in strategic settings. The centrality of these ideas explains why, despite the technical challenges involved, the literature on repeated games has grown rapidly in recent years. With their masterful treatment of many of the most important parts of this vast territory, Mailath and Samuelson have done a great service to both students and researchers."--David G. Pearce, Department of Economics, New York University Book Description Personalized and continuing relationships play a central role in any society. Economists have built upon the theories of repeated games and reputations to make important advances in understanding such relationships. Repeated Games and Reputations begins with a careful development of the fundamental concepts in these theories, including the notions of a repeated game, strategy, and equilibrium. Mailath and Samuelson then present the classic folk theorem and reputation results for games of perfect and imperfect public monitoring, with the benefit of the modern analytical tools of decomposability and self-generation. They also present more recent developments, including results beyond folk theorems and recent work in games of private monitoring and alternative approaches to reputations. Repeated Games and Reputations synthesizes and unifies the vast body of work in this area, bringing the reader to the research frontier. Detailed arguments and proofs are given throughout, interwoven with examples, discussions of how the theory is to be used in the study of relationships, and economic applications. The book will be useful to those doing basic research in the theory of repeated games and reputations as well as those using these tools in more applied research. </LI>
<LI>Contents 1 Introduction 1 1.1 Intertemporal Incentives 1 1.2 The Prisoners’ Dilemma 3 1.3 Oligopoly 4 1.4 The Prisoner’s Dilemma under Imperfect Monitoring 5 1.5 The Product-Choice Game 7 1.6 Discussion 8 1.7 A Reader’s Guide 10 1.8 The Scope of the Book 10 Part I Games with Perfect Monitoring 2 The Basic Structure of Repeated Games with Perfect Monitoring 15 2.1 The Canonical Repeated Game 15 2.1.1 The Stage Game 15 2.1.2 Public Correlation 17 2.1.3 The Repeated Game 19 2.1.4 Subgame-Perfect Equilibrium of the Repeated Game 22 2.2 The One-Shot Deviation Principle 24 2.3 Automaton Representations of Strategy Profiles 29 2.4 Credible Continuation Promises 32 2.5 Generating Equilibria 37 2.5.1 Constructing Equilibria: Self-Generation 37 2.5.2 Example: Mutual Effort 40 2.5.3 Example: The Folk Theorem 41 2.5.4 Example: Constructing Equilibria for Low δ 44 2.5.5 Example: Failure of Monotonicity 46 2.5.6 Example: Public Correlation 49 2.6 Constructing Equilibria: Simple Strategies and Penal Codes 51 2.6.1 Simple Strategies and Penal Codes 51 2.6.2 Example: Oligopoly 54 2.7 Long-Lived and Short-Lived Players 61 2.7.1 Minmax Payoffs 63 2.7.2 Constraints on Payoffs 66 x Contents 3 The Folk Theorem with Perfect Monitoring 69 3.1 Examples 70 3.2 Interpreting the Folk Theorem 72 3.2.1 Implications 72 3.2.2 Patient Players 73 3.2.3 Patience and Incentives 75 3.2.4 Observable Mixtures 76 3.3 The Pure-Action Folk Theorem for Two Players 76 3.4 The Folk Theorem with More than Two Players 80 3.4.1 A Counterexample 80 3.4.2 Player-Specific Punishments 82 3.5 Non-Equivalent Utilities 87 3.6 Long-Lived and Short-Lived Players 91 3.7 Convexifying the Equilibrium Payoff SetWithout Public Correlation 96 3.8 Mixed-Action Individual Rationality 101 4 How Long Is Forever? 105 4.1 Is the Horizon Ever Infinite? 105 4.2 Uncertain Horizons 106 4.3 Declining Discount Factors 107 4.4 Finitely Repeated Games 112 4.5 Approximate Equilibria 118 4.6 Renegotiation 120 4.6.1 Finitely Repeated Games 122 4.6.2 Infinitely Repeated Games 134 5 Variations on the Game 145 5.1 Random Matching 145 5.1.1 Public Histories 146 5.1.2 Personal Histories 147 5.2 Relationships in Context 152 5.2.1 A Frictionless Market 153 5.2.2 Future Benefits 154 5.2.3 Adverse Selection 155 5.2.4 Starting Small 158 5.3 Multimarket Interactions 161 5.4 Repeated Extensive Forms 162 5.4.1 Repeated Extensive-Form Games Have More Subgames 163 5.4.2 Player-Specific Punishments in Repeated Extensive-Form Games 165 5.4.3 Extensive-Form Games and Imperfect Monitoring 167 5.4.4 Extensive-Form Games and Weak Individual Rationality 168 5.4.5 Asynchronous Moves 169 5.4.6 Simple Strategies 172 Contents xi 5.5 Dynamic Games: Introduction 174 5.5.1 The Game 175 5.5.2 Markov Equilibrium 177 5.5.3 Examples 178 5.6 Dynamic Games: Foundations 186 5.6.1 Consistent Partitions 187 5.6.2 Coherent Consistency 188 5.6.3 Markov Equilibrium 190 5.7 Dynamic Games: Equilibrium 192 5.7.1 The Structure of Equilibria 192 5.7.2 A Folk Theorem 195 6 Applications 201 6.1 PriceWars 201 6.1.1 Independent Price Shocks 201 6.1.2 Correlated Price Shocks 203 6.2 Time Consistency 204 6.2.1 The Stage Game 204 6.2.2 Equilibrium, Commitment, and Time Consistency 206 6.2.3 The Infinitely Repeated Game 207 6.3 Risk Sharing 208 6.3.1 The Economy 209 6.3.2 Full Insurance Allocations 210 6.3.3 Partial Insurance 212 6.3.4 Consumption Dynamics 213 6.3.5 Intertemporal Consumption Sensitivity 219 Part II Games with (Imperfect) Public Monitoring 7 The Basic Structure of Repeated Games with Imperfect Public Monitoring 225 7.1 The Canonical Repeated Game 225 7.1.1 The Stage Game 225 7.1.2 The Repeated Game 226 7.1.3 Recovering a Recursive Structure: Public Strategies and Perfect Public Equilibria 228 7.2 A Repeated Prisoners’ Dilemma Example 232 7.2.1 Punishments Happen 233 7.2.2 Forgiving Strategies 235 7.2.3 Strongly Symmetric Behavior Implies Inefficiency 239 7.3 Decomposability and Self-Generation 241 7.4 The Impact of Increased Precision 249 7.5 The Bang-Bang Result 251 xii Contents 7.6 An Example with Short-Lived Players 255 7.6.1 Perfect Monitoring 256 7.6.2 Imperfect Public Monitoring of the Long-Lived Player 260 7.7 The Repeated Prisoners’ Dilemma Redux 264 7.7.1 Symmetric Inefficiency Revisited 264 7.7.2 Enforcing a Mixed-Action Profile 267 7.8 Anonymous Players 269 8 Bounding Perfect Public Equilibrium Payoffs 273 8.1 Decomposing on Half-Spaces 273 8.2 The Inefficiency of Strongly Symmetric Equilibria 278 8.3 Short-Lived Players 280 8.3.1 The Upper Bound on Payoffs 280 8.3.2 Binding Moral Hazard 281 8.4 The Prisoners’ Dilemma 282 8.4.1 Bounds on Efficiency: Pure Actions 282 8.4.2 Bounds on Efficiency: Mixed Actions 284 8.4.3 A Characterization with Two Signals 287 8.4.4 Efficiency with Three Signals 289 8.4.5 Efficient Asymmetry 291 9 The Folk Theorem with Imperfect Public Monitoring 293 9.1 Characterizing the Limit Set of PPE Payoffs 293 9.2 The Rank Conditions and a Public Monitoring Folk Theorem 298 9.3 Perfect Monitoring Characterizations 303 9.3.1 The Folk Theorem with Long-Lived Players 303 9.3.2 Long-Lived and Short-Lived Players 303 9.4 Enforceability and Identifiability 305 9.5 Games with a Product Structure 309 9.6 Repeated Extensive-Form Games 311 9.7 Games of Symmetric Incomplete Information 316 9.7.1 Equilibrium 318 9.7.2 A Folk Theorem 320 9.8 Short Period Length 326 10 Private Strategies in Games with Imperfect Public Monitoring 329 10.1 Sequential Equilibrium 329 10.2 A Reduced-Form Example 331 10.2.1 Pure Strategies 331 10.2.2 Public Correlation 332 10.2.3 Mixed Public Strategies 332 10.2.4 Private Strategies 333 10.3 Two-Period Examples 334 10.3.1 Equilibrium Punishments Need Not Be Equilibria 334 10.3.2 Payoffs by Correlation 337 10.3.3 Inconsistent Beliefs 338 Contents xiii 10.4 An Infinitely Repeated Prisoner’s Dilemma 340 10.4.1 Public Transitions 340 10.4.2 An Infinitely Repeated Prisoners’ Dilemma: Indifference 343 11 Applications 347 11.1 Oligopoly with Imperfect Monitoring 347 11.1.1 The Game 347 11.1.2 Optimal Collusion 348 11.1.3 Which News Is Bad News? 350 11.1.4 Imperfect Collusion 352 11.2 Repeated Adverse Selection 354 11.2.1 General Structure 354 11.2.2 An Oligopoly with Private Costs: The Game 355 11.2.3 A Uniform-Price Equilibrium 356 11.2.4 A Stationary-Outcome Separating Equilibrium 357 11.2.5 Efficiency 359 11.2.6 Nonstationary-Outcome Equilibria 360 11.3 Risk Sharing 365 11.4 Principal-Agent Problems 370 11.4.1 Hidden Actions 370 11.4.2 Incomplete Contracts: The Stage Game 371 11.4.3 Incomplete Contracts: The Repeated Game 372 11.4.4 Risk Aversion: The Stage Game 374 11.4.5 Risk Aversion: Review Strategies in the Repeated Game 375 Part III Games with Private Monitoring 12 Private Monitoring 385 12.1 ATwo-Period Example 385 12.1.1 Almost Public Monitoring 387 12.1.2 Conditionally Independent Monitoring 389 12.1.3 Intertemporal Incentives from Second-Period Randomization 392 12.2 Private Monitoring Games: Basic Structure 394 12.3 Almost Public Monitoring: Robustness in the Infinitely Repeated Prisoner’s Dilemma 397 12.3.1 The Forgiving Profile 398 12.3.2 Grim Trigger 400 12.4 Independent Monitoring: A Belief-Based Equilibrium for the Infinitely Repeated Prisoner’s Dilemma 404 12.5 A Belief-Free Example 410 13 Almost Public Monitoring Games 415 13.1 When Is Monitoring Almost Public? 415 13.2 Nearby Games with Almost Public Monitoring 418 xiv Contents 13.2.1 Payoffs 418 13.2.2 Continuation Values 419 13.2.3 Best Responses 421 13.2.4 Equilibrium 421 13.3 Public Profiles with Bounded Recall 423 13.4 Failure of Coordination under Unbounded Recall 425 13.4.1 Examples 425 13.4.2 Incentives to Deviate 427 13.4.3 Separating Profiles 428 13.4.4 Rich Monitoring 432 13.4.5 Coordination Failure 434 13.5 Patient Players 434 13.5.1 Patient Strictness 435 13.5.2 Equilibria in Nearby Games 437 13.6 A Folk Theorem 441 14 Belief-Free Equilibria in Private Monitoring Games 445 14.1 Definition and Examples 445 14.1.1 Repeated Prisoners’ Dilemma with Perfect Monitoring 447 14.1.2 Repeated Prisoners’ Dilemma with Private Monitoring 451 14.2 Strong Self-Generation 453 Part IV Reputations 15 Reputations with Short-Lived Players 459 15.1 The Adverse Selection Approach to Reputations 459 15.2 Commitment Types 463 15.3 Perfect Monitoring Games 466 15.3.1 Building a Reputation 470 15.3.2 The Reputation Bound 474 15.3.3 An Example: Time Consistency 477 15.4 Imperfect Monitoring Games 478 15.4.1 Stackelberg Payoffs 480 15.4.2 The Reputation Bound 484 15.4.3 Small Players with Idiosyncratic Signals 492 15.5 Temporary Reputations 493 15.5.1 Asymptotic Beliefs 494 15.5.2 Uniformly Disappearing Reputations 496 15.5.3 Asymptotic Equilibrium Play 497 15.6 Temporary Reputations: The Proof of Proposition 15.5.1 500 15.6.1 Player 2’s Posterior Beliefs 500 15.6.2 Player 2’s Beliefs about Her Future Behavior 502 Contents xv 15.6.3 Player 1’s Beliefs about Player 2’s Future Behavior 503 15.6.4 Proof of Proposition 15.5.1 509 16 Reputations with Long-Lived Players 511 16.1 The Basic Issue 511 16.2 Perfect Monitoring and Minmax-Action Reputations 515 16.2.1 Minmax-Action Types and Conflicting Interests 515 16.2.2 Examples 518 16.2.3 Two-Sided Incomplete Information 520 16.3 Weaker Reputations for Any Action 521 16.4 Imperfect Public Monitoring 524 16.5 Commitment Types Who Punish 531 16.6 Equal Discount Factors 533 16.6.1 Example 1: Common Interests 534 16.6.2 Example 2: Conflicting Interests 537 16.6.3 Example 3: Strictly Dominant Action Games 540 16.6.4 Example 4: Strictly Conflicting Interests 541 16.6.5 Bounded Recall 544 16.6.6 Reputations and Bargaining 546 16.7 Temporary Reputations 547 17 Finitely Repeated Games 549 17.1 The Chain Store Game 550 17.2 The Prisoners’ Dilemma 554 17.3 The Product-Choice Game 560 17.3.1 The Last Period 562 17.3.2 The First Period, Player 1 562 17.3.3 The First Period, Player 2 565 18 Modeling Reputations 567 18.1 An Alternative Model of Reputations 568 18.1.1 Modeling Reputations 568 18.1.2 The Market 570 18.1.3 Reputation with Replacements 573 18.1.4 How Different Is It? 576 18.2 The Role of Replacements 576 18.3 Good Types and Bad Types 580 18.3.1 Bad Types 580 18.3.2 Good Types 581 18.4 Reputations with Common Consumers 584 18.4.1 Belief-Free Equilibria with Idiosyncratic Consumers 585 18.4.2 Common Consumers 586 18.4.3 Reputations 587 18.4.4 Replacements 588 18.4.5 Continuity at the Boundary and Markov Equilibria 590 18.4.6 Competitive Markets 594 xvi Contents 18.5 Discrete Choices 596 18.6 Lost Consumers 599 18.6.1 The Purchase Game 599 18.6.2 Bad Reputations: The Stage Game 600 18.6.3 The Repeated Game 601 18.6.4 Incomplete Information 603 18.6.5 Good Firms 607 18.6.6 Captive Consumers 608 18.7 Markets for Reputations 610 18.7.1 Reputations Have Value 610 18.7.2 Buying Reputations 613 Bibliography 619 Symbols 629 Index 631 </LI>