This study tests the rationality of the decisions to purchase information, the informational efficiency of prices, and the optimality of the resulting allocations with a series of laboratory experiments in decentralized markets. The theory predicts that markets with dispersed information and...

We use measures of neural activity provided by functional magnetic resonance imaging (fMRI) to test the "realization utility" theory of investor behavior, which posits that people derive utility directly from the act of realizing gains and losses. Subjects traded stocks in an experimental market...

We study how markets help spread knowledge about solutions to the standard but computationally hard problem of maximizing value over indivisible goods subject to a budget constraint. In a first experiment, we f ind that complete markets are fairly ineffective. Still, participants use prices and...

Asset pricing theorists have recently started to study the market impact of differences in beliefs among participants. The analysis is often carried out in the framework of Radner's perfect foresight ('rational expectations') equilibrium. Here, we study when this makes sense. In particular, we...

The non-medical use of pharmaceuticals such as methylphenidate and modafinil for cognitive enhancement has been explored in college students, medical students and various professions in the US and Europe. We present results of an anonymous online survey of such use among members of the...

We study information aggregation in financial markets. We introduce two new stability concepts: absolute stability (sensitivity of rational expectations equilibrium prices to signals (bits) that are lost or garbled), and relative stability (the difference between prices in the rational...

We consider a canonical asset pricing model, where agents with quadratic preferences are allowed to retrade a limited set of securities over multiple periods, after which these securities expire, and agents consume their liquidation values. A key assumption in this model is that agents have...

We analyze theoretically and empirically the implications of heterogeneous information for equilibrium asset pricing and portfolio choice. Our theoretical framework, directly inspired by Admati (1985), implies that with partial information aggregation, portfolio separation fails, buy-and-hold...

The cross-section of average annual returns on German common stock in the period of 1881-1913 exhibits several of the patterns that have been observed in more recent U.S. data. Market beta is hardly important, and its explanatory power is swamped by size and the ratio of book value to market...

We report on experiments of simple, repeated asset markets in two risky securities and one risk-free security, set up to test the Capital Asset Pricing Model (CAPM), which embeds the two most essential principles of modern asset pricing theory, namely, (i) financial markets equilibrate, (ii) in...