Information and Learning in Markets

Xavier Vives is professor of economics and finance at IESE Business School in Barcelona. He is the author of "Oligopoly Pricing: Old Ideas and New Tools".

• Preface xi Introduction and Lecture Guide 1 References 12 Chapter 1: Aggregation of Information in Simple Market Mechanisms: Large Markets 15 1.1 Introduction and Overview 15 1.2 Large Cournot Markets 17 1.3 Welfare in Large Cournot Markets with Asymmetric Information 27 1.4 Information Aggregation in Smooth Large Markets 29 1.5 Auctions and Voting 38 1.6 Endogenous Information Acquisition 40 1.7 Summary 45 1.8 Appendix 46 1.9 Exercises 48 References 51 Chapter 2: Aggregation of Information in Simple Market Mechanisms: How Large Is Large? 53 2.1 A General Linear-Normal Cournot Model 54 2.2 Convergence to Price Taking in a Cournot Market 57 2.3 Endogenous Information Acquisition 58 2.4 Convergence to the First-Best: Market Power and Information Aggregation 62 2.5 Convergence in Auctions 67 2.6 Summary 70 2.7 Appendix 71 2.8 Exercises 74 References 76 Chapter 3: Rational Expectations and Supply Function Competition 78 3.1 Rational Expectations Equilibrium: Concepts, Problems, and Welfare 78 3.2 Supply Function Competition and REE in a Continuum Economy 84 3.3 Welfare Analysis of REE 95 3.4 Strategic Supply Function Equilibria and Convergence to a Price-Taking Equilibrium 98 3.5 Double Auctions 100 3.6 Summary 102 3.7 Appendix 102 3.8 Exercises 103 References 105 Chapter 4: Rational Expectations and Market Microstructure in Financial Markets 107 4.1 Market Microstructure 108 4.2 Competitive Rational Expectations Equilibria 112 4.3 Informed Traders Move First and Face Risk-Neutral Competitive Market Makers 130 4.4 Hedgers and Producers in a Futures Market 135 4.5 Summary 145 4.6 Appendix 147 4.7 Exercises 148 References 152 Chapter 5: Strategic Traders in Financial Markets 156 5.1 Competition in Demand Schedules 157 5.2 Informed Traders Move First 168 5.3 Market Makers Move First 177 5.4 An Application: Welfare Analysis of Insider Trading 183 5.5 Summary 189 5.6 Exercises 190 References 195 Chapter 6: Learning from Others and Herding 199 6.1 Herding, Informational Cascades, and Social Learning 200 6.2 Extensions of the Herding Model 204 6.3 A Smooth and Noisy Model of Learning from Others 210 6.4 Applications and Examples 222 6.5 The Information Externality and Welfare 227 6.6 Rational Expectations, Herding, and Information Externalities 236 6.7 Summary 239 6.8 Appendix 240 6.9 Exercises 241 References 244 Chapter 7: Dynamic Information Aggregation 248 7.1 Rational Expectations, Full-Information Equilibria, and Learning 248 7.2 Learning and Convergence to a Full-Information Equilibrium with Uninformed Firms 253 7.3 Market Dynamics with Asymmetric Information 257 7.4 Slow Learning and Convergence 261 7.5 Summary 266 7.6 Appendix 267 7.7 Exercises 271 References 273 Chapter 8: Dynamic Rational Expectations Models in Competitive Financial Markets 276 8.1 Dynamic Competitive Rational Expectations 277 8.2 The Impact of Risk-Averse Market Makers 285 8.3 Dynamic Trading with Short-Term Investors 294 8.4 Explaining Crises and Market Crashes 306 8.5 Summary 318 8.6 Appendix 320 8.7 Exercises 324 References 326 Chapter 9: Price and Information Dynamics in Financial Markets 330 9.1 Sequential Trading, Dynamic Market-Order Markets, and the Speed of Learning from Past Prices 331 9.2 Strategic Trading with Long-Lived Information 339 9.3 Market Manipulation and Price Discovery 347 9.4 Strategic Trading with Short-Lived Information 355 9.5 Strategic Hedging 358 9.6 Summary 360 9.7 Appendix 361 9.8 Exercises 362 References 365 Chapter 10: Technical Appendix 369 10.1 Information Structures and Bayesian Inference 369 10.2 Normal Distributions and Affine Information Structure 375 10.3 Convergence Concepts and Results 383 10.4 Games and Bayesian Equilibrium 390 References 398 Index 401

"[R]eading Professor Vives's prose was a joy. His explanations for why various results obtain are clear and the flow from model to model is natural. Results in later chapters are frequently related to results in earlier chapters, tying the whole book together... [I]t is an excellent reference."--Lawrence R. Glosten, Journal of Economic Literature "Written in a simple and easy to understand language and providing an intuitive analysis of sophisticated models, this work can be a valuable reference for graduate courses in financial economics and microeconomics. Also, being thought-provoking, I find this book to be excellent reading material for researchers who work in both the asset pricing and market microstructure areas."--Leon Zolotoy, Economic Record