1.
‘The All-Pay Auction with Complete Information and Identity-Dependent Externalities’, coauthor Bettina Klose
We show how the presence of identity-dependent externalities invalidates well established qualitative results concerning the set of equilibria of the first-price all-pay auction with complete information. With identity-dependent externalities equilibria are in general not payoff equivalent, and identical players may earn different payoffs in equilibrium. Moreover, equilibrium payoffs may be greater than or less than equilibrium payoffs in a first-price winner-pay auction with identical valuations. These observations show that Siegel’s (2009) results characterizing the set of equilibrium payoffs in all-pay contests do not extend to environments with identity-dependent externalities.

2.
‘Extremism drives Out Moderation’ , coauthor Bettina Klose

This article investigates the impact of the distribution of preferences on equilibrium behavior in conflicts that are modeled as all-pay auctions with identity-dependent externalities. In this context, we define centrists and radicals using a willingness-to pay criterion that admits preferences more general than a simple ordering on the line. Through a series of examples, we show that substituting the auction contest success function for the lottery contest success function in a conflict may alter the relative expenditures of centrists and radicals in equilibrium. Extremism, characterized by a higher per capita expenditure by radicals than centrists, may persist and lead to a higher aggregate expenditure by radicals, even when they are relatively small in number. Moreover, we show that centrists may in the aggregate expend zero, even if they vastly outnumber radicals. Our results highlight the importance of the choice of the institutions of conflict, as modeled by the contest success function, in determining the role of extremism and moderation in economic, political, and social environments.