Strategic manipulability of self-selective social choice rules

CNRS 2; AERES AInternational audienceWe provide exact relations giving the probability of individual and coalitional manipulation of three specific social choice functions (Borda rule, Copeland rule, Plurality rule) in three-alternative elections when the notion of self-selectivity is imposed. We use each type of tie-breaking rule in the case of three-candidate election in order to make the results more robust. Analyzing our probabilities, we can point out that the probability of individual and coalitional manipulation tend to vanish significantly when the notion of self-selectivity is imposed