My research interests are Economic Theory, Networks, Game Theory and Mechanism Design.
Social connections provide various benefits, such as access to information, support, and collaboration, motivating individuals to form networks. However, in many social settings-like academic conferences or networking events-participants are initially strangers, making the networking process inherently anonymous and random. This paper incorporates anonymity into the canonical non-cooperative connections model (Bala and Goyal (2000)) to explore symmetric, mixed-strategy equilibria in network formation. We show that, for any trembling-hand perfect equilibrium, strategies can be interpreted as socialization effort and yield a random network, closely related to but distinct from classical Erdős-Rényi graphs. This provides a strategic microfoundation for random graphs. We fully characterize these equilibria and efficient networks for large populations as a function of connection costs.
A group of agents with ex-ante independent and identically uncertain quality compete for a prize, awarded by a principal. Agents may possess evidence about the quality of those they share a social connection with (neighbours), and themselves. In one equilibrium, adversarial disclosure of evidence leads the principal to statistically discriminate between agents based on their number of neighbours (degree). We identify parameter values for which an agent’s ex-ante winning probability is monotone in degree. All equilibria that satisfy some robustness criteria lie between this adverse disclosure equilibrium and a less informative one that features no snitching and no discrimination.
The previous versions of this paper are Self-Ratings and Peer Review (2018) and Identifying the Best Agent in a Network (2017). First version: 2016.
A principal must allocate a prize without monetary transfers. She wants to give it to the highest value agent. Agents know their own and their neighbors’ values, as determined by a network. Competing for the prize, agents send messages about themselves (applications) and their neighbors (references). They face a limit to lying, so information is partially verifiable. No incentive-compatible mechanism achieves robust implementation. Assigning the prize as a function of best applications and worst references achieves dominant strategy implementation for all networks and full implementation for the complete network and a class of networks if agents are partially honest.
We explore the dynamics of demand for n designs of a good when agents have preferences for (anti-)conformity. Agents differ in their social status and each agent seeks to imitate those of higher status and to distinguish herself from those of lower status, relative to her own status. In each period, every agent chooses a design given each agent's demand in the previous period. We show that demand dynamics resemble fashion cycles: The demand for designs is repetitively bell-shaped over time, and, when positively demanded, a design trickles from high- to low-status individuals. At least for n=3, the demand dynamics converge to a unique limit cycle. We obtain a similar (though weaker) convergence result for n=4, and simulations suggest that the result holds for n=4 and 5.
The previous version of this paper is Time Allocation in Friendship Networks (2015). First version: 2014.
The paper proposes a game of weighted network formation in which each agent has a limited resource to form links of possibly different intensities with other agents and to use for private purposes. We show that every equilibrium is either "reciprocal" or "non-reciprocal". In a reciprocal equilibrium, any two agents invest equally in the link between them. In a non-reciprocal equilibrium, agents are partitioned into "concentrated" and "diversified" agents and a concentrated agent is only linked to diversified agents and vice versa. For every link, the concentrated agent invests more in the link than the diversified agent. The unweighted relationship graph of an equilibrium, in which two agents are linked if they both invest positively in each other, uniquely predicts the equilibrium values of each agent's network investment and utility level, as well as the ratio of any two agents' investments in each other. We show that equilibria are not pairwise stable and not efficient due to the positive externalities of investing in a link.