@conference {531556,
	title = {Social Choice with Non Quasi-linear Utilities},
	booktitle = {Proceedings of the 2018 ACM Conference on Economics and Computation (EC{\textquoteright}18)},
	year = {2018},
	month = {2018},
	pages = {49-49},
	abstract = {
Without monetary payments, the Gibbard-Satterthwaite theorem proves that under mild requirements all truthful social choice mechanisms must be dictatorships. When payments are allowed, the Vickrey-Clarke-Groves (VCG) mechanism implements the value-maximizing choice, and has many other good properties: it is strategy-proof, onto, deterministic, individually rational, and does not make positive transfers to the agents. By Roberts{\textquoteright} theorem, with three or more alternatives, the weighted VCG mechanisms are essentially  unique for domains with quasi-linear utilities. The goal of this paper is to characterize domains of non-quasi-linear utilities where {\textquoteleft}{\textquoteleft}reasonable{\textquoteright}{\textquoteright} mechanisms (with VCG-like properties) exist. Our main result is a tight characterization of the maximal non quasi-linear utility domain, which we call the largest parallel domain. We extend Roberts{\textquoteright} theorem to parallel domains, and use the generalized theorem to prove two impossibility results. First, any reasonable mechanism must be dictatorial when the utility domain is quasi-linear together with any single non-parallel type. Second, for richer utility domains that still differ very slightly from quasi-linearity, every strategy-proof, onto and deterministic mechanism must be a dictatorship.

\&nbsp;},
	url = {https://arxiv.org/abs/1804.02268},
	author = {Hongyao Ma and Reshef Meir and David C. Parkes}
}
