The complexity of testing properties of simple games

Simple games cover voting systems in which a single alternative, such as a bill or an amendment, is pitted against the status quo. A simple game or a yes-no voting system is a set of rules that specifies exactly which collections of ``yea'' votes yield passage of the issue at hand. A colle...

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Detalles Bibliográficos
Autores: Freixas Bosch, Josep|||0000-0002-9033-9432, Molinero Albareda, Xavier|||0000-0002-5203-4347, Olsen, Martin, Serna Iglesias, María José|||0000-0001-9729-8648
Tipo de recurso: informe técnico
Fecha de publicación:2008
País:España
Institución:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2117/103171
Acceso en línea:https://hdl.handle.net/2117/103171
Access Level:acceso abierto
Palabra clave:Game theory
Voting--Mathematical models
Simple
Weighted
Majority Games
NP-Completeness
Jocs, Teoria de
Vot -- Models matemàtics
Classificació AMS::91 Game theory, economics, social and behavioral sciences::91A Game theory
Àrees temàtiques de la UPC::Matemàtiques i estadística::Investigació operativa::Teoria de jocs
Descripción
Sumario:Simple games cover voting systems in which a single alternative, such as a bill or an amendment, is pitted against the status quo. A simple game or a yes-no voting system is a set of rules that specifies exactly which collections of ``yea'' votes yield passage of the issue at hand. A collection of ``yea'' voters forms a winning coalition. We are interested on performing a complexity analysis of problems on such games depending on the game representation. We consider four natural explicit representations, winning, loosing, minimal winning, and maximal loosing. We first analyze the computational complexity of obtaining a particular representation of a simple game from a different one. We show that some cases this transformation can be done in polynomial time while the others require exponential time. The second question is classifying the complexity for testing whether a game is simple or weighted. We show that for the four types of representation both problem can be solved in polynomial time. Finally, we provide results on the complexity of testing whether a simple game or a weighted game is of a special type. In this way, we analyze strongness, properness, decisiveness and homogeneity, which are desirable properties to be fulfilled for a simple game.