Deparment of Economics
I am an Assistant Professor of Economics at Fordham University. My research is in microeconomic theory, in particular, decision theory, game theory, and networks. Previously, I was an Assistant Professor of Economics at the W.P. Carey School of Business at Arizona State University.
Revealed Preference Implications of Backward Induction and Subgame Perfection (American Economic Journal: Microeconomics, Vol. 12, May 2020, pages 230-56)
Frictions in Internet Auctions with Many Traders: a Counterexample, with Javier Donna and Gregory Veramendi (Economic Letters, Volume 138, January 2016, Pages 81-84)
Identifying subjective beliefs in subjective state space models (Games and Economic Behavior, Vol. 95, (January 2016), Pages 59–72)
We propose a decision-theoretic model akin to Savage (1972) that is useful for defining causal effects. Within this framework, we define what it means for a decision maker (DM) to act as if the relation between the two variables is causal. Next, we provide axioms on preferences and show that these axioms are equivalent to the existence of a (unique) Directed Acyclic Graph (DAG) that represents the DM's preference. The notion of representation has two components: the graph factorizes the conditional independence properties of the DM's subjective beliefs, and arrows point from cause to effect. Finally, we explore the connection between our representation and models used in the statistical causality literature (for example, Pearl (1995)).
Most decision problems can be understood as a mapping from a preference space into an abstract set of outcomes. When preferences are representable via utility functions, this generates a mapping from a space of utility functions into outcomes. We say a model is continuous in utilities (resp., preferences) if small perturbations of utility functions (resp., preferences) generate small changes in outcomes. While similar, these two concepts are equivalent only when the topology satisfies the following universal property: for each continuous mapping from preferences to outcomes there is a unique mapping from utilities to outcomes that is faithful to the preference map and is continuous. The topologies that satisfy such a universal property are called final topologies. In this paper we analyze the properties of the final topology for preference sets. This is of practical importance since most of the analysis o, continuity is done via utility functions and not the primitive preference space. Our results allow the researcher to extrapolate continuity in utility to continuity in the underlying preferences.
This paper studies repeated games of incomplete information where each player knows his own payoffs and where the unknown state of the world can be identified by the combined private information of all players. We obtain a condition that is both necessary and sufficient for a Perfect Bayesian Equilibrium (PBE) folk theorem to hold. This contrasts with the existing literature where, due to the difficulty in keeping track of beliefs as play evolves, the analysis has focused on either Nash equilibrium for one-sided incomplete information or has dealt with various ex-post solution concepts. Finally, we also show the condition obtained is also necessary and sufficient to obtain Ex-Post folk theorems.