Twin peaks: Expressive externality in group participation

David Levine, Salvatore Modica, Junze Sun

Research output: Contribution to journalArticlepeer-review


We introduce a model of group behavior that combines expressive participation with strategic participation. Building on the idea that expressive voting in elections is much like rooting for a sports team, we give applications to both sporting events and elections. In our model there is an expressive externality: an individual enjoys an event more when more of her peers come out to support her preferred party or team. We show that this results in the possibility of “tipping”—that participation may jump up discontinuously when the externality becomes strong enough. We examine the implications for pricing by sports teams and for voter turnout.
Original languageEnglish
Pages (from-to)897-929
Number of pages33
JournalJournal of Public Economic Theory
Issue number5
Early online date31 May 2023
Publication statusPublished - Oct 2023


  • expressive voting
  • externality
  • group behavior
  • peer punishment
  • sports

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