Consistency and the exclusion core under co-ownership

Abstract

In discrete allocation with co-ownership, the exclusion core of Balbuzanov and Kotowski (2019) grants owners exclusion rights and secures nonemptiness by keeping unaffected agents out of blocking coalitions. This restriction can defeat legitimate ownership claims and make the exclusion core's prediction hinge on agents who have nothing at stake. Consistency diagnoses this failure and dictates the repair: an unaffected group that could depart with its assignments may join a blocking coalition, but only to complete the coalition's joint exclusion right. The resulting consistent exclusion core is the largest consistent refinement of the exclusion core and remains nonempty. Consistency has a price: no strategy-proof mechanism selects from any nonempty, consistent, Pareto efficient, and individually rational solution, including the consistent exclusion core. The conflict vanishes when every object is privately or publicly owned: the consistent exclusion core then coincides with the exclusion core and admits a strategy-proof selection.

arXiv commentAdd a characterization of the largest consistent refinement of the exclusion core, and prove an impossiblity result about strategy-proof selection from consistent solutions