We survey the recent literature on learning in financial markets. Our main theme is that many financial market phenomena that appear puzzling at first sight are easier to understand once we recognize that parameters in financial models are uncertain and subject to learning. We discuss phenomena...

Several recent studies have attributed a large part of asset price volatility to self-fulfilling expectations. Such an explanation is unattractive to many since it allows allocations that need bear no particular relation to those implied by the economist's standard kit of

What risks do asset price bubbles pose for the economy? This paper studies bubbles in housing and equity markets in 17 countries over the past 140 years. History shows that not all bubbles are alike. Some have enormous costs for the economy, while others blow over. We demonstrate that what makes...

We explore the implications of asset price volatility for the management of monetary policy. We show that it is desirable for central banks to focus on underlying inflationary pressures. Asset prices become relevant only to the extent they may signal potential inflationary or deflationary...

This paper presents evidence on attitude changes among investors in the US stock market. Two basic attitudes are explored: bubble expectations and investor confidence. Semiannual time-series indicators of these attitudes are presented for US stock market institutional investors based on...

This paper reports empirical tests for the existence of rational bubbles in stock prices. The analysis focuses on a familiar model that defines market fundamentals to be the expected present value of dividends, discounted at a constantrate, and defines a rational bubble to be a self-confirming...

A rational bubble would involve a self-confirming belief that an asset price depends on information that includes variables or parameters that are not part of market fundamentals. The existing literature shows that, if market fundamentals are economically interesting, i.e., forward looking, any...