Pundits and Quacks

Do asset prices aggregate investors’ private information about the ability of financial analysts? We show that as financial analysts become reputable, the market can get trapped: Investors optimally choose to ignore their private information, and blindly follow analyst recommendations. As time goes by and recommendations accumulate, arbitrage based on the inferred ability of analysts may become profitable again. The market can thus be trapped at times and yet be able, in the long run, to sort the pundits from the quacks. However, this process is impaired when asset fundamentals are volatile: in this case, the market might be trapped indefinitely

Attack, defence, and contagion in networks

© The Author 2014. Connections between individuals facilitate the exchange of goods, resources, and information and create benefits. These connections may be exploited by adversaries to spread their attacks as well. What is the optimal way to design and defend networks in the face of attacks? We develop a model with a Designer and an Adversary. The Designer moves first and chooses a network and an allocation of defence resources across nodes. The Adversary then allocates attack resources on nodes; if an attack succeeds then the Adversary decides on how successful resources should navigate the network. We obtain two principal results. One, we show that in a wide variety of circumstances a star network with all defence resources allocated to the central node is optimal for the Designer. Two, we identify conditions on the technology of conflict, network value function, and the resource configuration for which networks with multiple hubs/components are optimal

Sorting and Grading

We propose a framework to assess how to optimally sort and grade students of heterogenous ability. Potential employers face uncertainty regarding an individual's productive value. Knowing which school an individual went to is useful for two reasons: firstly, average student ability may differ across schools; secondly, different schools may use different grading rules and thus provide varying incentives to exert effort. An optimal school system exhibits coarse stratification with respect to ability, and more lenient grading at the top-tier schools than at the bottom-tier schools. Our paper contributes to the ongoing policy debate on tracking in secondary schools.Comment: 27 pages, 1 figur

Who acquires information in dealer markets?

We study information acquisition in dealer markets. We first identify a one- sided strategic complementarity in information acquisition: the more informed traders are, the larger market makers’ gain from becoming informed. When quotes are observable, this effect in turn induces a strategic complementarity in information acquisition amongst market makers. We then derive the equilibrium pattern of information acquisition and examine the implications of our analysis for market liquidity and price discovery. We show that increasing the cost of information can decrease market liquidity and improve price discovery

Learning about analysts

We examine an analyst with career concerns making cheap talk recommendations to a sequence of traders, each of whom possesses private information concerning the analyst's ability. The recommendations of the analyst influence asset prices that are then used to evaluate the analyst. An endogeneity problem thus arises. In particular, if the reputation of the analyst is sufficiently high then an incompetent but strategic analyst is able to momentarily hide her type. An equilibrium in which the market eventually learns the analyst type always exists. However, under some conditions, an equilibrium also exists in which the incompetent analyst is able to hide her type forever

Dynamic Persuasion with Outside Information

A principal seeks to persuade an agent to accept an offer of uncertain value before a deadline expires. The principal can generate information, but exerts no control over exogenous outside information. The combined effect of the deadline and outside information creates incentives for the principal to keep uncertainty high in the first periods so as to persuade the agent close to the deadline. We characterize the equilibrium, compare it to the single-player decision problem in which exogenous outside information is the agent's only source of information, and examine the welfare implications of our analysis

Competing for Talent

In many labor markets, e.g., for lawyers, consultants, MBA students, and professional sport players, workers get offered and sign long-term contracts even though waiting could reveal significant information about their capabilities. This phenomenon is called unraveling. We examine the link between wage bargaining and unraveling. Two firms, an incumbent and an entrant, compete to hire a worker of unknown talent. Informational frictions prevent the incumbent from always observing the entrant’s arrival, inducing unraveling in all equilibria. We analyze the extent of unraveling, surplus shares, the average talent of employed workers, and the distribution of wages within and across firms

Dynamic persuasion with outside information

A principal seeks to persuade an agent to accept an offer of uncertain value before a deadline expires. The principal can generate information, but exerts no control over exogenous outside information. The combined effect of the deadline and outside information creates incentives for the principal to keep uncertainty high in the first periods so as to persuade the agent close to the deadline. We characterize the equilibrium, compare it to the single-player decision problem in which exogenous outside information is the agent's only source of information, and examine the welfare implications of our analysis

Financial Experts, Asset Prices and Reputation

We analyze how financial experts influence asset prices in a sequential trading model. In the model, an expert of unknown ability sends a report about asset values to traders, who then observe a signal about the expert's type. All information about the expert's ability is private to traders and only revealed through trades. When the expert's reputation is sufficiently high, traders ignore their private signal about ability and the market enters a reputational cascade in which no information about the expert reaches the market. Reputational cascades are conducive to asset price bubbles, which eventually result in market crashes when cascades terminate. Rather than being caused by the release of new information, market crashes in our model result from the sudden depreciation of past accumulated information. Finally, we show that reputational cascades are bad for liquidity and induce high price volatility

Who Acquires Information in Dealer Markets?

We study information acquisition in dealer markets. We first identify a one-sided strategic complementarity in information acquisition: the more informed traders are, the larger market makers' gain from becoming informed. When quotes are observable, this effect in turn induces a strategic complementarity in information acquisition amongst market makers. We then derive the equilibrium pattern of information acquisition and examine the implications of our analysis for market liquidity and price discovery. We show that increasing the cost of information can decrease market liquidity and improve price discovery