Large long-run swings in the United States stock market over the past century correspond to swings in estimates of fundamental values calculated by using a long moving average of past dividend growth to forecast future growth rates. Such a procedure would have been reasonable if investors were...

The major bull and bear markets of this century have suggested to many that large decade-to-decade stock market swings reflect irrational "fads and fashions" that periodically sweep investors. We argue instead that investors have perceived significant shifts in the long-run mean rate of future...