Two-Group Contests with Communication Within and Between Groups

  • Federico Quartieri
  • Ryusuke Shinohara
Part of the Springer Series in Game Theory book series (SSGT)


We consider a two-group contest game with weakest-link social composition functions and convex cost functions and prove the existence of a unique group-proof Nash equilibrium. Such a refinement of the Nash equilibrium prescribes the same communication possibilities as those required by a coalition-proof Nash equilibrium—in the precise sense of Bernheim et al. (J Econ Theory 42:1–12, 1987)—only among the contenders of the same group and between the two groups. We show how a fictitious game with “most inefficient fictitious contenders” can be constructed to prove the existence of a unique group-proof Nash equilibrium of the original two-group contest game. An example evidences that cautious arguments on the (twice) differentiability of cost functions must be used in such a construction.


Nash Equilibrium Payoff Function Contest Success Function General Nash Equilibrium Nash Equilibrium Uniqueness 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



The first author gratefully acknowledges financial support: part of his work was carried out in the frame of Programme STAR, financially supported by UniNA and Compagnia di San Paolo. The second author gratefully acknowledges JSPS KAKENHI Grant Number 15K03361.


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© Springer International Publishing Switzerland 2016

Authors and Affiliations

  1. 1.Dipartimento di scienze economiche e statisticheUniversità degli studi di Napoli Federico IINaplesItaly

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