California Institute of Technology
1200 E. California Blvd. MC 228-77
Pasadena, CA 91125
Information about this author at RePEc
NBER Working Papers and Publications
|January 2016||Extrapolation and Bubbles|
with Nicholas Barberis, Robin Greenwood, Andrei Shleifer: w21944
We present an extrapolative model of bubbles. In the model, many investors form their demand for a risky asset by weighing two signals—an average of the asset’s past price changes and the asset’s degree of overvaluation. The two signals are in conflict, and investors “waver” over time in the relative weight they put on them. The model predicts that good news about fundamentals can trigger large price bubbles. We analyze the patterns of cash-flow news that generate the largest bubbles, the reasons why bubbles collapse, and the frequency with which they occur. The model also predicts that bubbles will be accompanied by high trading volume, and that volume increases with past asset returns. We present empirical evidence that bears on some of the model’s distinctive predictions.
|June 2013||X-CAPM: An Extrapolative Capital Asset Pricing Model|
with Nicholas Barberis, Robin Greenwood, Andrei Shleifer: w19189
Survey evidence suggests that many investors form beliefs about future stock market returns by extrapolating past returns: they expect the stock market to perform well (poorly) in the near future if it performed well (poorly) in the recent past. Such beliefs are hard to reconcile with existing models of the aggregate stock market. We study a consumption-based asset pricing model in which some investors form beliefs about future price changes in the stock market by extrapolating past price changes, while other investors hold fully rational beliefs. We find that the model captures many features of actual prices and returns, but is also consistent with the survey evidence on investor expectations. This suggests that the survey evidence does not need to be seen as an inconvenient obstacle to u...
Published: Barberis, Nicholas & Greenwood, Robin & Jin, Lawrence & Shleifer, Andrei, 2015. "X-CAPM: An extrapolative capital asset pricing model," Journal of Financial Economics, Elsevier, vol. 115(1), pages 1-24. citation courtesy of