What caused the rise and fall of tech stocks? I argue that a mechanism much like the transactions demand for money drove many stock prices above the 'fundamental value' they would have had in a frictionless market. I start with the Palm/3Com microcosm and then look at tech stocks in general....

Will the stock market provide high returns in the future as it has in the past? The average US stock return in the postwar period has been about 8% above treasury bill rates. But that average is poorly measured: The standard confidence interval extends from 3% to 13%. Furthermore, expected...

This essay examines what volatility tests tell us about the data and what implications we should derive from them. It argues that volatility tests do not tell us that "prices are too volatile", implying that "markets are inefficient", but rather that "(discounted) returns are forecastable",...

The investment return is defined as the real return that results from marginally increasing investment at date r, and then reaping the extra output and decreasing investment at date t+1 to leave the production plan for other dates unchanged. This paper constructs investment returns from...

This paper presents a bound on the variance of the price-dividend ratio and a decomposition of the variance of the price-dividend ratio into components that reflect variation in expected future discount rates and variation in expected future dividend growth. Unobserved discount rates needed to...

If stocks go up, investors may want to rebalance their portfolios. But investors cannot all rebalance. Expected returns may need to change so that the average investor is still happy to hold the market portfolio despite its changed composition. In this way, simple market clearing can give rise...