Abstract
It is well known that many aggregation rules are manipulable through strategic behaviour. Typically, the aggregation rules considered in the literature are social choice correspondences. In this paper the aggregation rules of interest are social welfare functions (SWFs). We investigate the problem of constructing a SWF that is non-manipulable. In this context, individuals attempt to manipulate a social ordering as opposed to a social choice. Using techniques from an ordinal version of fuzzy set theory, we introduce a class of ordinally fuzzy binary relations of which exact binary relations are a special case. Operating within this family enables us to prove an impossibility theorem. This theorem states that all non-manipulable SWFs are dictatorial, provided that they are not constant. This theorem uses a weaker transitivity condition than the one in Perote-Peña and Piggins (J Math Econ 43:564–580, 2007), and the ordinal framework we employ is more general than the cardinal setting used there. We conclude by considering several ways of circumventing this impossibility theorem.
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References
Abdelaziz FB, Figueira JR, Meddeb O (2008) On the manipulability of the fuzzy social choice functions. Fuzzy Sets Syst 159: 177–184
Arrow KJ (1951) Social choice and individual values. Wiley, New York
Banerjee A (1994) Fuzzy preferences and Arrow-type problems in social choice. Soc Choice Welf 11: 121–130
Barberá S (2001) An introduction to strategy-proof social choice functions. Soc Choice Welf 18: 619–653
Barrett CR, Pattanaik PK (1989) Fuzzy sets, preference and choice: some conceptual issues. Bull Econ Res 41: 229–253
Barrett CR, Pattanaik PK, Salles M (1986) On the structure of fuzzy social welfare functions. Fuzzy Sets Syst 19: 1–10
Barrett CR, Pattanaik PK, Salles M (1992) Rationality and aggregation of preferences in an ordinally fuzzy framework. Fuzzy Sets Syst 49: 9–13
Basu K, Deb R, Pattanaik PK (1992) Soft sets: an ordinal reformulation of vagueness with some applications to the theory of choice. Fuzzy Sets Syst 45: 45–58
Billot A (1995) Economic theory of fuzzy equilibria. Springer, Berlin
Bossert W, Storcken T (1992) Strategy-proofness of social welfare functions: the use of the Kemeny distance between preference orderings. Soc Choice Welf 9: 345–360
Broome J (1997) Is incommensurability vagueness. In: Chang R Incommensurability, incomparability, and practical reason. Harvard University Press, Harvard
Côrte-Real PP (2007) Fuzzy voters, crisp votes. Int Game Theory Rev 9: 67–86
Dasgupta M, Deb R (1996) Transitivity and fuzzy preferences. Soc Choice Welf 13: 305–318
Dasgupta M, Deb R (1999) An impossibility theorem with fuzzy preferences. In: de Swart H (ed) Logic, game theory and social choice: proceedings of the international conference. LGS ’99, May 13–16. Tilburg University Press, Tilburg
Dasgupta M, Deb R (2001) Factoring fuzzy transitivity. Fuzzy Sets Syst 118: 489–502
Dutta B (1987) Fuzzy preferences and social choice. Math Soc Sci 13: 215–229
Fono LA, Andjiga NG (2005) Fuzzy strict preference and social choice. Fuzzy Sets Syst 155: 372–389
Fishburn PC (1970) Comments on Hansson’s “Group preferences”. Econometrica 38: 933–935
Gaertner W (2006) A primer in social choice theory. Oxford University Press, Oxford
Gibbard AF (1973) Manipulation of voting schemes: a general result. Econometrica 41: 587–601
Goguen JA (1967) L-fuzzy sets. J Math Anal Appl 18: 145–174
Leclerc B (1984) Efficient and binary consensus functions on transitively valued relations. Math Soc Sci 8: 45–61
Leclerc B (1991) Aggregation of fuzzy preferences: a theoretic Arrow-like approach. Fuzzy Sets Syst 43: 291–309
Leclerc B, Monjardet B (1995) Lattical theory of consensus. In: Barnett W, Moulin H, Salles M, Schofield N Social choice, welfare and ethics. Cambridge University Press, Cambridge
Ovchinnikov SV (1991) Social choice and Lukasiewicz logic. Fuzzy Sets Syst 43: 275–289
Pattanaik PK (1973) On the stability of sincere voting situations. J Econ Theory 6: 558–574
Perote-Peña J, Piggins A (2007) Strategy-proof fuzzy aggregation rules. J Math Econ 43: 564–580
Perote-Peña J, Piggins A (2009a) Non-manipulable social welfare functions when preferences are fuzzy. J Logic Comput 19: 503–515
Perote-Peña J, Piggins A (2009b) Social choice, fuzzy preferences and manipulation. In: Boylan T, Gekker R Economics, rational choice and normative philosophy. Routledge, London
Piggins A, Salles M (2007) Instances of indeterminacy. Anal Kritik 29: 311–328
Richardson G (1998) The structure of fuzzy preferences: social choice implications. Soc Choice Welf 15: 359–369
Salles M (1998) Fuzzy utility. In: Barbera S, Hammond PJ, Seidl C Handbook of utility theory, vol 1: principles. Kluwer, Dordrecht
Satterthwaite M (1975) Strategy-proofness and Arrow’s conditions: existence and correspondence theorems for voting procedures and social welfare functions. J Econ Theory 10: 187–217
Sen AK (1970a) Interpersonal aggregation and partial comparability. Econometrica 38: 393–409
Sen AK (1970b) Collective choice and social welfare. Holden-Day, San Francisco
Tang F-F (1994) Fuzzy preferences and social choice. Bull Econ Res 46: 263–269
Taylor AD (2005) Social choice and the mathematics of manipulation. Cambridge University Press, Cambridge
Williamson T (1994) Vagueness. Routledge, London
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We are grateful to seminar participants at NUI Galway, King’s College London, Universität Osnabrück, Queen’s University Belfast and PET 08 for comments and suggestions. In addition, we would like to thank Nick Baigent, James Jordan, Christian List, Andrew McLennan, Vincent Merlin, Maurice Salles and two anonymous referees for a number of helpful remarks. Financial support from the Spanish Ministry of Science and Innovation through Feder grant SEJ2007-67580-C02-02, the NUI Galway Millennium Fund and the Irish Research Council for the Humanities and Social Sciences is gratefully acknowledged.
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Duddy, C., Perote-Peña, J. & Piggins, A. Manipulating an aggregation rule under ordinally fuzzy preferences. Soc Choice Welf 34, 411–428 (2010). https://doi.org/10.1007/s00355-009-0405-5
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DOI: https://doi.org/10.1007/s00355-009-0405-5