The notion that the value of an asset is the present value of the cash flows that you expect to generate by holding it is neither new nor revolutionary. The earliest interest rate tables date back to 1340, and the intellectual basis for discounted cash flow valuation was laid by Alfred Marshall and Bohm-Bawerk in the early part of the twentieth century. The principles of modern valuation were developed by Irving Fisher in two books—The Rate of Interest in 1907 and The Theory of Interest in 1930.