1.1.. INTRODUCTION1.2.. SOURCES OF BEHAVIORAL CONVERGENCE1.3.. RATIONAL LEARNING AND INFORMATION CASCADES: BASIC IMPLICATIONS1.4.. WHAT IS COMMUNICATED OR OBSERVED?1.5.. PSYCHOLOGICAL BIAS1.6.. REPUTATION, CONTRACTS, AND HERDING1.7.. SECURITY ANALYSIS1.8.. HERD BEHAVIOR AND CASCADES IN SECURITY TRADING1.9.. MARKETS, EQUILIBRIUM PRICES, AND BUBBLES1.10.. CASCADES AND HERDING IN FIRM BEHAVIOR1.11.. CONTAGION OF FINANCIAL MEMES1.12.. CONCLUSION