Rationality, path independence, and the power structure

The justification of the requirement of consistency in aggregating individual preferences is to make the choice rational and path independent. This paper shows that a Paretian social choice mechanism that satisfies even the weakest rationality requirement which is related to the principle of some sort of maximization or path independence alone generates an extremely asymmetric power structure, e.g., almost dictatorship. Consequently, some well-known and interesting impossibility results are generalized.