We show that the stock market may fail to aggregate information even if it appears to be efficient and that the resulting decrease in the information content of stock prices may drastically reduce welfare. We solve a macroeconomic model in which information about fundamentals is dispersed and...

This paper performs a welfare analysis of economies with private information when public information is endogenously generated and agents can condition on noisy public statistics in the rational expectations tradition. We find that equilibrium is not (restricted) efficient even when feasible...

We examine whether Brazilian sovereign spreads of over 20% in 2002 could be due to contagion from Argentina or to domestic politics, or both. Treating unilateral debt restructuring as a policy variable gives rise to the possibility of self-fulfilling crisis, which can be triggered by contagion....

We develop a theoretical framework to quantitatively assess the general equilibrium effects and welfare implications of central bank reputation and transparency. Monetary policy alternates between periods of active inflation stabilization and periods during which the emphasis on inflation...

Eleven percent of the Malawian population is HIV infected. Eighteen percent of sexual encounters are casual. A condom is used one quarter of the time. A choice-theoretic general equilibrium search model is constructed to analyze the Malawian epidemic. In the developed framework, people select...

We study a stylized theory of the volatility reduction in the U.S. after 1984 - the Great Moderation - which attributes part of the stabilization to less volatile shocks and another part to more difficult inference on the part of Bayesian households attempting to learn the latent state of the...

Building on evidence from neurobiology and neuroscience, we model the physiological limitations faced by individuals in the process of decision-making that starts with sensory perception and ends in action selection. The brain sets a neuronal threshold, observes whether the neuronal cell firing...

The paper re-examines the efficiency hypothesis in the foreign exchange market. The traditional efficiency testing equations are reviewed and a model is developed that incorporates Bayesian revisions in the form of devaluation expectations. A number of propositions regarding the pattern of the...

We analyze a two-player game of strategic experimentation with two-armed bandits. Each player has to decide in continuous time whether to use a safe arm with a known payoff or a risky arm whose likelihood of delivering payoffs is initially unknown. The quality of the risky arms is perfectly...

We develop a multi-period model of strategic trading in an asset market where traders are uncertain about market liquidity. In our model, informed traders strategically trade against competitive market makers to exploit their short-lived private information. Unlike market makers, informed...