An analysis of the Barcelona Town Council 2023–2027 using the proportional partitional Shapley value

We discuss the strategic situation in the Barcelona Town Council after the elections held on May 28, 2023. This institution is described as a simple game, and the Shapley–Shubik index is applied to measure the initial power distribution among the parties. We introduce some ideological incompatibilit...

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Detalles Bibliográficos
Autores: Carreras Escobar, Francisco|||0000-0002-7248-9912, Magaña Nieto, Antonio|||0000-0003-0879-0759
Tipo de recurso: artículo
Fecha de publicación:2026
País:España
Institución:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:dnet:upcommonspor::7c662679d4b91054c74d66652355150b
Acceso en línea:https://hdl.handle.net/2117/461183
https://dx.doi.org/10.1007/s11750-026-00714-9
Access Level:acceso abierto
Palabra clave:Simple and weighted majority game
Incompatibility restriction
Shapley–Shubik power index
Coalition structure
Proportional partitional Shapley value
Stability
Àrees temàtiques de la UPC::Matemàtiques i estadística
Descripción
Sumario:We discuss the strategic situation in the Barcelona Town Council after the elections held on May 28, 2023. This institution is described as a simple game, and the Shapley–Shubik index is applied to measure the initial power distribution among the parties. We introduce some ideological incompatibilities in the game and, finally, we discuss the existence of stable coalition structures in the different stated scenarios when the power payoffs to the players are computed using the proportional partitional Shapley value. The key point is the formation of a stable coalition structure. Broadly speaking, a coalition structure is stable if the payoff obtained by each player cannot be increased by a unilateral change in their choice of coalition. In a previous paper, we showed that any simple game admits stable coalition structures when the payoffs are computed using the proportional partitional Shapley value. We find the stable coalition structures for each of the situations analyzed. The results show a fairly complicated problem that the involved politicians and parties should try to solve for the benefit of Barcelona citizens.