Standard models of informed speculation suggest that traders try to learn information that others do not have. This result implicitly relies on the assumption that speculators have long horizons, i.e, can hold the asset forever. By contrast, we show that if speculators have short horizons, they...

This paper examines equilibrium and welfare in a tractable class of economies with externalities, strategic complementarity or substitutability, and incomplete information. In equilibrium, complementarity amplifies aggregate volatility by increasing the sensitivity of actions to public...

We calculate equilibria of dynamic double-auction markets in which agents are distinguished by their preferences and information. Over time, agents are privately informed by bids and offers. Investors are segmented into groups that differ with respect to characteristics determining information...

Using a comprehensive sample of trades by Schedule 13D filers, who possess valuable private information when they accumulate stocks of targeted companies, this paper studies whether several liquidity measures reveal the presence of informed trading. The evidence suggests that when Schedule 13D...

In absence of insurance contracts to share risk, public information is a double-edged sword. On the one hand, it empowers self-insurance as agents better react to shocks, reducing risk. On the other hand, it weakens market-insurance as common knowledge of shocks restricts trading risk. We embody...

Is an economy with adverse selection, moral hazard, or an incomplete set of risk markets "constrained" Pareto efficient? There are two sets of papers addressing this question, one asserting that, under seemingly quite general conditions, the economy is constrained Pareto efficient, the other (to...

This paper presents a simple general equilibrium model of asset pricing in which profitable informed trading can occur without any "noise" added to the model. It shows that models of profitable informed trading must restrict the portfolio choices of uninformed traders: in particular, they cannot...

In efficient markets the price should reflect the arrival of private information. The mechanism by which this is accomplished is arbitrage. A privately informed trader will engage in costly arbitrage, that is, trade on his knowledge that the price of an asset is different from the fundamental...

This paper studies the welfare effects of the relative price variability arising from inflation. When agents interact in anonymous markets, with customers buying from new suppliers each period, relative price variability benefits customers and cannot harm suppliers substantially. But if...

An information externality exists in the foreign exchange market due to the fact that traders play two partially conflicting roles: (i) each is a speculator and (ii) each is an information clearinghouse in that each intermediates own-customer orders which convey information. Profit maximization...