Search Results
Working Paper
Superstar Economists: Coauthorship networks and research output
We study the impact of research collaborations in coauthorship networks on research output and how optimal funding can maximize it. Through the links in the collaboration network, researchers create spillovers not only to their direct coauthors but also to researchers indirectly linked to them. We characterize the equilibrium when agents collaborate in multiple and possibly overlapping projects. We bring our model to the data by analyzing the coauthorship network of economists registered in the RePEc Author Service. We rank the authors and research institutions according to their contribution ...
Journal Article
The Trade-Offs of Counterterrorism Policies
This article provides a modern overview of counterterrorism tools and their trade-offs for curbing terrorist attacks and their consequences. Defensive and proactive countermeasures constitute two main classes of counterterror tools deployed by targeted governments. The primary drawback of defensive actions, which make terrorist attacks more costly and less apt to succeed, is attack transference that shifts the mode, venue, or target of attacks to those less protected. In contrast, offensive proactive measures, which confront the terrorists directly, may result in backlash as terrorist ...
Working Paper
Voluntary participation in a terror group and counterterrorism policy
A three-stage game investigates how counterterrorism measures are affected by volunteers’ choice in joining a terrorist group. In stage 1, the government chooses both proactive and defensive countermeasures, while looking ahead to the anticipated size and actions of terrorist groups. After radicalized individuals choose whether to join a terrorist group in stage 2, group members then allocate their time between work and terrorist operations. Based on wages and government counterterrorism, the game characterizes the extensive margin determining group size and the intensive margin ...
Working Paper
The boy who cried bubble: public warnings against riding bubbles
Attempts by governments to stop bubbles by issuing warnings seem unsuccessful. This paper examines the effects of public warnings using a simple model of riding bubbles. We show that public warnings against a bubble can stop it if investors believe that a warning is issued in a definite range of periods commencing around the starting period of the bubble. If a warning involves the possibility of being issued too early, regardless of the starting period of the bubble, it cannot stop the bubble immediately. Bubble duration can be shortened by a premature public warning, but lengthened if it is ...
Report
Anxiety and pro-cyclical risk taking with Bayesian agents
We provide a model that can explain empirically relevant variations in confidence and risk taking by combining horizon-dependent risk aversion (?anxiety?) and selective memory in a Bayesian intrapersonal game. In the time series, overconfidence is more prevalent when actual risk levels are high, while underconfidence occurs when risks are low. In the cross section, more anxious agents are more prone to biased confidence and their beliefs fluctuate more. This systematic variation in confidence levels can lead to objectively excessive risk taking by ?insiders? with the potential to amplify ...
Report
Gender discrimination and social identity: experimental evidence from urban Pakistan
Gender discrimination in South Asia is a well-documented fact. However, gender is only one of an individual?s many identities. This paper investigates how gender discrimination depends on the social identities of interacting parties. We use an experimental approach to identify gender discrimination by randomly matching 2,836 male and female students pursuing bachelor?s-equivalent degrees in three different types of institutions?Madrassas (religious seminaries), Islamic universities, and liberal universities?that represent distinct identities within the Pakistani society. Our main finding is ...
Working Paper
Collusion in Repeated Auctions with Costless Communication
In this paper, we present a model of repeated first-price private value auctions in which the bidders have access to a cheap talk communication mechanism. In this framework, messages allow bidders to transmit their preference rankings over the goods to be auctioned, similar to Pesendorfer (2000). We show that collusion through this static mechanism not only dominates the static bid rotation mechanism presented by McAfee and McMillan (1992), but it is also not strictly dominated by the dynamic bid rotation mechanism presented by Aoyagi (2003). However, we show that asymptotic efficiency of ...
Working Paper
Financial Contracting with Enforcement Externalities
We study the negative feedback loop between the aggregate default rate and the efficacy of enforcement in a model of debt-financed entrepreneurial activity. The novel feature of our model is that enforcement capacity is accumulated ex ante and thus subject to depletion ex post. We characterize the effect of shocks that deplete enforcement resources on the aggregate default rate and credit supply. In the model default decisions by entrepreneurs are strategic complements, leading to multiple equilibria. We propose a global game selection to overcome equilibrium indeterminacy and show how shocks ...
Working Paper
Collaboration in Bipartite Networks, with an Application to Coauthorship Networks
This paper studies the impact of collaboration on research output. First, we build a micro founded model for scientific knowledge production, where collaboration between researchers is represented by a bipartite network. The equilibrium of the game incorporates both the complementarity effect between collaborating researchers and the substitutability effect between concurrent projects of the same researcher. Next, we develop a Bayesian MCMC procedure to estimate the structural parameters, taking into account the endogenous matching of researchers and projects. Finally, we illustrate the ...
Working Paper
Collateral Runs
This paper models an unexplored source of liquidity risk faced by large broker-dealers: collateral runs. By setting different contracting terms on repurchase agreements with cash borrowers and lenders, dealers can source funds for their own activities. Cash borrowers internalize the risk of losing their collateral in case their dealer defaults, prompting them to withdraw it. This incentive creates strategic complementarities for counterparties to withdraw their collateral, reducing a dealer's liquidity position and compromising her solvency. Collateral runs are markedly different than ...