We model two interacting contagion processes: one of disease and one of fear of the disease. Individuals can contract fear through contact with individuals who are infected with the disease (the sick), infected with fear only (the scared), and infected with both fear and disease (the sick and...

Equilibrium analysis pervades mathematical social science. This paper calls into question the explanatory significance of equilibrium by offering an extremely simple game, most of whose equilibria are unattainable in principle from any of its initial conditions. Moreover, the number of...

This paper provides an independent review and evaluation of the PBGC's Pension Insurance Modeling System (PIMS). Our analysis suggests that the PIMS model was, in many ways, “state-of-the-art” when it was created approximately two decades ago. However, several key components of the model...

Canonical models of rational choice fail to account for many forms of motivated adaptive behaviors, specifically in domains such as food selections. To describe behavior in such emotion- and reward-laden scenarios, researchers have proposed dual-process models that posit competition between a...

Ethnocentrism is a nearly universal syndrome of attitudes and behaviors, typically including in-group favoritism. Empirical evidence suggests that a predisposition to favor in-groups can be easily triggered by even arbitrary group distinctions and that preferential cooperation within groups...

Biographical note: EpsteinJoshua M.: Joshua M. Epstein is a Senior Fellow in Economic Studies at the Brookings Institution, a founding member of the Brookings-Johns Hopkins Center on Social and Economic Dynamics, and a member of the External Faculty of the Santa Fe Institute. He is the coauthor...