Coalitional Stability in a Class of Social Interactions Games

Hideo Konishi, Michel Le Breton and Shlomo Weber

No 1098, Boston College Working Papers in Economics from Boston College Department of Economics

Abstract: In this paper, we define additive dyadic social interactions games (ADG), in which each player cares not only about the selected action, but also about interactions with other players, especially those who choose the same action. This class of games includes alliance formation games, network games, and dis- crete choice problems with network externalities. While it is known that games in the ADG class admit a pure strategy Nash equilibrium that is a maximizer of the game's potential, the potential approach does not always apply if all coalitional deviations are allowed. We then introduce a novel notion of a strong landscape equilibrium, which relies on a limited scope of coalitional deviations. We show the existence of a strong landscape equilibrium for a class of basic additive dyadic social interactions games (BADG), even though a strong Nash equilibrium may fail to exist. Somewhat surprisingly, a potential-maximizing strong landscape equilibrium is not always a strong Nash equilibrium even if the set of the latter is nonempty. We also provide applications and extensions of our results.

Keywords: Social Interactions Game; Potential Function; Coalition Formation; Strong Nash Equilibrium; Strong Landscape Equilibrium (search for similar items in EconPapers)
JEL-codes: C71 C72 C78 (search for similar items in EconPapers)
Date: 2025-10-25
New Economics Papers: this item is included in nep-des, nep-evo, nep-mic and nep-net
References: Add references at CitEc
Citations:

Downloads: (external link)
http://fmwww.bc.edu/EC-P/wp1098.pdf main text (application/pdf)

Related works:
Working Paper: Coalitional Stability in a Class of Social Interactions Games (2025)
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:boc:bocoec:1098

Access Statistics for this paper

More papers in Boston College Working Papers in Economics from Boston College Department of Economics Boston College, 140 Commonwealth Avenue, Chestnut Hill MA 02467 USA. Contact information at EDIRC.
Bibliographic data for series maintained by Christopher F Baum ().