Financial Theory (ECON 251) This lecture gives a brief history of the young field of financial theory, which began in business schools quite separate from economics, and of my growing interest in the field and in Wall Street. A cornerstone of standard financial theory is the efficient markets hypothesis, but that has been discredited by the financial crisis of 2007-09. This lecture describes the kinds of questions standard financial theory nevertheless answers well. It also introduces the leverage cycle as a critique of standard financial theory and as an explanation of the crisis. The lecture ends with a class experiment illustrating a situation in which the efficient markets hypothesis works surprisingly well. 00:00 - Chapter 1. Course Introduction 10:16 - Chapter 2. Collateral in the Standard Theory 17:54 - Chapter 3. Leverage in Housing Prices 33:47 - Chapter 4. Examples of Finance 46:13 - Chapter 5. Why Study Finance? 50:13 - Chapter 6. Logistics 58:22 - Chapter 7. A Experiment of the Financial Market Complete course materials are available at the Yale Online website: online.yale.edu This course was recorded in Fall 2009.