Social Choice and Game Theory

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Research interests

• I became interested in power indices with the debate that took place before the enlargement of the European Union to Austria, Finland and Sweden. I started to apply the power indices to two voting rules that had been proposed for the enlarged Council of Ministers and got bewitched by the question. Since then, I have been interested in a variety of topics related to this problem, as the voting power concept and measurement, the meaning of power indices, the question of success and decisiveness the design of decision procedures, and the turnout in elections. My first co-author was the late Mika Widgrén (last affiliation Turku School of Economics) but I have mainly worked with Federico Valenciano (UPV/EHU). I also worked with Josune Albizuri (UPV/EHU), Alaitz Artabe (UPV/EHU), Constanza Fosco (Universidad Católica del Norte), Ricardo Martínez (Universidad Carlos III de Madrid), Vincent Merlin (Université de Caen and CRNS) and Anxo Sanchez (Universidad Carlos III de Madrid).

 

• Why, in elections, can voters only express satisfaction with a single candidate/party? Why can't they voice their dissatisfaction with some candidates? Why aren't they asked their opinion on all candidates? In order to allow voter to express better their preferences toward candidates alternative rules could be used. In particular, voters could be asked their opinion on every candidate/party, i.e. whether they approve, disapprove or are indifferent. The study of this rule is a recent project that I have initiated in collaboration with Jose Carlos R. Alcantud (Universidad de Salamanca). 

 

• A few years ago the biologist Imma Estevez (Neiker and IKERBASQUE) contacted us about a an experiment of hers with domestic fowls. When a proportions of the population is marked (on the back of their heads), the marked birds suffer more aggression. The introduction of artificial heterogeneity (through marking) may thus modify the animal behavior. Elena Iñarra (UPV/EHU) and I got interested by this question. In a first step, we have proposed a variation of the classical hawk-dove game where individuals are unaware of their own type but see their opponent's type. More generally we are interested in problematic of discrimination. Two other co-authors on this topic are André Barreiras da Silva Rocha (University of Leicester) and Peio Zuazo (UPV/EHU).

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Selected publications

• Bargaining in Committees as an extension of Nash’s bargaining theory, 2007, Journal of Economic Theory 132(1), 291-305. Joint with F. Valenciano.

• Voting and Collective Decision-Making: Bargaining and Power, 2008, Cambridge University Press, Cambridge, New York. Joint with F. Valenciano.
• Egalitarianism and utilitarianism in committees of representatives, 2010, Social Choice and Welfare 35(2), 221-243. Joint with F. Valenciano.
• Turnout Intention and Social Networks, 2011, Advances in Complex Systems 14(1), 31-53. Joint with C. Fosco and A. Sanchez. 
• Artificial Distinction and Real Discrimination, 2012, Journal of Theoretical Biology 305, 110-117. Joint with E. Iñarra.

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