We study how sophisticated investors, when faced with changes in information environment, adjust their information acquisition and trading behavior, and how these changes in turn affect market efficiency. We find that, after exogenous reductions of analyst coverage due to closures of brokerage...

Limits to arbitrage play a central role in behavioral finance. They are thought to interfere with arbitrage processes so that security prices can deviate from true values for extended periods of time. We describe a recent financial innovation that allows limits to arbitrage to be sidestepped,...

We study the interplay of share prices and firm decisions when share prices aggregate and convey noisy information about fundamentals to investors and managers. First, we show that the informational feedback between the firm's share price and its investment decisions leads to a systematic...

Motivated by psychological evidence that attention is a scarce cognitive resource, we model investors' attention allocation in learning and study the effects of this on asset-price dynamics. We show that limited investor attention leads to ``category-learningquot; behavior, i.e., investors tend...

Stock prices are more informative when the information has less social value. Speculators with limited resources making costly (private) information production decisions must decide to produce information about some firms and not others. We show that producing and trading on private information...

In a capitalist economy prices serve to equilibrate supply and demand for goods and services, continually changing to reallocate resources to their most efficient uses. However, secondary stock market prices, often viewed as the most 'informationally efficient' prices in the economy, have no...

Equity market liberalizations are like IPOs, but they are IPOs of a country's stock market rather than of individual firms. Both are endogenous events whose benefits are limited by poor investor protection, agency costs, and information asymmetries. As for stock prices following an IPO, there...

Large institutional investors own an increasing share of the equity markets in the U.S. The implications of this development for financial markets are still unclear. The paper presents novel empirical evidence that ownership by large institutions predicts higher volatility and greater noise in...

This paper is about the effectiveness of qualitative easing, a form of unconventional monetary policy that changes the risk composition of the central bank balance sheet with the goal of stabilizing economic activity. We construct a general equilibrium model where agents have rational...