Willemien Kets

MEDS, Kellogg School of Management

Phone: +1 (505) 204-8012
Email: w-kets@kellogg.northwestern.edu

Curriculum Vitae


A belief-based theory of homophily (with Alvaro Sandroni)

Can the tendency of individuals to interact with others that are similar to themselves can be rooted in something besides homophilous preferences? Buiding on the dual process account of Theory of Mind in psychology, we show that homophily can emerge even in the absence of homophilous preferences because players find it easier to put themselves in each other's shoes when they share a similar background. The model yields novel comparative statics, and we investigate welfare implications.

Bounded Reasoning and Higher-Order Uncertainty (submitted).

Experimental evidence suggests that players have a finite depth of reasoning. Nevertheless, common belief can often be attained, e.g., through a public announcement. This paper introduces a framework that can resolve this paradox. I show that common belief does not entail high-order mutual belief, unlike in the standard case.

Finite Depth of Reasoning and Equilibrium Play in Games with Incomplete Information (submitted).
Online appendix.

If players have a finite depth of reasoning, can their equilibrium behavior be described by the standard framework? Intuitively, one might expect that “simple” Harsanyi type spaces, in which the beliefs of types are determined by the first few orders of beliefs, would be good “as-if models” models for finite-depth type spaces. However, I show that this is not the case: for any finite-depth type space, there is no Harsanyi type space (simple or not simple) that gives the same equilibrium behavior in all games.

Robust Multiplicity with a Grain of Naiveté (with Aviad Heifetz; submitted).
Online appendix.

In global games and other games with sufficiently rich payoffs, types typically have a unique rationalizable action (Weinstein & Yildiz, '07). This result, however, presumes that players have an infinite depth of reasoning and that this is common belief. We show that multiplicity of rationalizable outcomes is a typical and robust phenomenon if we relax that assumption only slightly, i.e., if players have an infinite depth and this is almost common belief.


Ambiguous Language and Consensus (with Joe Halpern), Games and Economic Behavior, forthcoming, 2014.

Ranking Friends (with Yossi Feinberg), Journal of Economic Behavior and Organization, forthcoming, 2014.
(Working paper version.)

Robustness of equilibria in anonymous local games, Journal of Economic Theory, 146, pp. 300–325, 2011.
Online appendix.
(Working paper version.)

Inequality and network structure (with Garud Iyengar, Rajiv Sethi and Sam Bowles), Games and Economic Behavior 73, pp. 215–226, 2011.
(Working paper version.)

Learning to be prepared (with Mark Voorneveld), International Journal of Game Theory 37, pp. 333–352, 2008.
(Working paper version.)

An axiomatization of minimal curb sets (with Mark Voorneveld and Henk Norde), International Journal of Game Theory 33, pp. 479–490, 2005.
(Working paper version.)

Publications in Other Fields

Betting Strategies, Market Selection, and the Wisdom of Crowds (with David Pennock, Rajiv Sethi and Nisarg Shah); Twenty-Eighth AAAI Conference on Artificial Intelligence (AAAI-14), 2014; forthcoming.

A logic for reasoning about ambiguity (with Joe Halpern); Artificial Intelligence, 2014; forthcoming.

Ambiguous language and differences in beliefs. Proceedings of KR2012, 2012. Ray Reiter Best Paper Award.

Random intersection graphs with a tunable degree distribution and clustering (with Mia Deijfen), Probability in the Engineering and Informational Sciences 23, pp. 661–674, 2008.

Zn- and Cd-induced features at the GaAs(110) and InP(110) surfaces studied by low-temperature scanning tunneling microscopy (with Randy de Kort, Maurice van der Wielen, Ari van Roij, and Herman van Kempen), Physical Review B 63, 125336, 2001.

A low-temperature scanning tunneling microscopy study on the Sn- and Zn-doped InP(110) surfaces (with Randy de Kort and Herman van Kempen), Surface Science 482, pp. 495–500, 2001.

Peer-Reviewed Surveys

Learning with fixed rules: The minority game, Journal of Economic Surveys. Forthcoming.

Free trade and its enemies (with Paul Tang), De Economist, pp. 152–153, pp. 427–437, 2004.