9AM GMT (6AM Rio de Janeiro, 9AM London, 10AM Paris, 12PM Istanbul, 2:30PM New Delhi, 5PM Shanghai, 6PM Tokyo/Seoul, 8PM Sydney, 10PM Auckland)
Huaxia Zeng (School of Economics, SUFE) "Equity in Strategic Exchange"
Host: Marcus Pivato
Abstract. New fairness notions aligned with the merit principle are proposed for designing exchange rules. We show that for an obviously strategy-proof, efficient and individually rational rule, (i) an agent receives her favorite object when others unanimously perceive her object the best, if and only if preferences are single-peaked, and (ii) an upper bound on fairness attainable is that, if two agents' objects are considered the best by all agents partitioned evenly into two groups, it is guaranteed that one, not both, gets her favorite object. This indicates an unambiguous trade-off between incentives and fairness in the design of exchange rules.
(Joint work with Peng Liu)
2PM GMT (9AM Montréal/Toronto, 11AM Rio de Janeiro, 2PM London, 3PM Graz, 5PM Istanbul, 7:30PM New Delhi, 11PM Tokyo/Seoul)
Steven Kivinen (University of Graz) "Robust Median Voter Rules"
Host: Marcus Pivato
Abstract. Generalized median voter (GMV) rules on the single-peaked preference domain are group strategy-proof. We show that if incomplete information coexists with the ability to commit to coalitional agreements, then GMV rules can be susceptible to insincere voting by groups with heterogeneous beliefs. We identify strategic compromise as a novel source of insincere voting in this environment. Our two main results characterize the set of fair, efficient, and robust voting rules: those that ensure sincere voting under asymmetric information and coalition formation. Each result uses a different notion of robustness, and both give (at most) two alternatives special treatment, with the remaining alternatives chosen according to a type of consensus.
(Joint work with Norovsambuu Tumennasan)
8PM GMT (12PM Vancouver, 2PM Austin, 3PM Toronto/Montréal, 5PM Rio de Janeiro, 8PM London, 9PM Paris, 11PM Istanbul, 9AM Wednesday in Auckland)
Harvey Lederman (University of Texas, Austin) "Maximal Social Welfare Relations on Infinite Populations Satisfying Permutation Invariance"
Host: Marcus Pivato
Abstract. We study social welfare relations (SWRs) on an infinite population. Our main result is a characterization of the common core shared by prominent utilitarian SWRs over distributions which realize finitely many welfare levels on this population. We characterize them as the largest SWR (with respect to set-inclusion when the weak relation is viewed as a set of pairs) which satisfies Strong Pareto, Permutation Invariance (elsewhere called ``Relative Anonymity'' and ``Isomorphism Invariance''), and a further ``Pointwise Independence'' axiom.
(Joint work with Jeremy Goodman)