Philosophers and theologians have railed against interest for thousands of years. But that is because they didn't understand what causes interest. Irving Fisher built a model of financial equilibrium on top of general equilibrium (GE) by introducing time and assets into the GE model. He saw that trade between apples today and apples next year is completely analogous to trade between apples and oranges today. Similarly he saw that in a world without uncertainty, assets like stocks and bonds are significant only for the dividends they pay in the future, just like an endowment of multiple goods. With these insights Fisher was able to show that he could solve his model of financial equilibrium for interest rates, present value prices, asset prices, and allocations with precisely the same techniques we used to solve for general equilibrium. He concluded that the real rate of interest is a relative price, and just like any other relative price, is determined by market participants' preferences and endowments, an insight that runs counter to the intuitions held by philosophers throughout much of human history. His theory did not explain the nominal rate of interest or inflation, but only their ratio.

1. Why Finance?
2. Utilities, Endowments, and Equilibrium
3. Computing Equilibrium
4. Efficiency, Assets, and Time
5. Present Value Prices and the Real Rate of Interest
6. Irving Fisher's Impatience Theory of Interest
7. Shakespeare's Merchant of Venice, Collateral. Present Value and the Vocabulary of Finance
8. How a Long-Lived Institution Figures an Annual Budget. Yield
9. Yield Curve Arbitrage
10. Dynamic Present Value
11. Social Security
12. Overlapping Generations Models of the Economy
13. Demography and Asset Pricing: Will the Stock Market Decline when the Baby Boomers Retire?
14. Quantifying Uncertainty and Risk
15. Uncertainty and the Rational Expectations Hypothesis
16. Backward Induction and Optimal Stopping Times
17. Callable Bonds and the Mortgage Prepayment Option
18. Modeling Mortgage Prepayments and Valuing Mortgages
19. History of the Mortgage Market: A Personal Narrative
20. Dynamic Hedging
21. Dynamic Hedging and Average Life
22. Risk Aversion and the Capital Asset Pricing Theorem
23. The Mutual Fund Theorem and Covariance Pricing Theorems
24. Risk, Return, and Social Security
25. The Leverage Cycle and the Subprime Mortgage Crisis
26. The Leverage Cycle and Crashes

This course attempts to explain the role and the importance of the financial system in the global economy. Rather than separating off the financial world from the rest of the economy, financial equilibrium is studied as an extension of economic equilibrium. The course also gives a picture of the kind of thinking and analysis done by hedge funds.

Course Structure:
This Yale College course, taught on campus twice per week for 75 minutes, was recorded for Open Yale Courses in Fall 2009.