Sequential Pseudomarkets and the Weak Core in Random Assignments, working paper

We study random assignment economies with expected-utility agents, each of them eventually obtaining a single object. The assignment should respect object-invariant priorities such as seniority rights in student residence as-signment, grandfather rights in landing slot assignment... We introduce the new Sequential Pseudomarket (SP) mech-anism, where the set of agents is partitioned into ordered priority groups that are called in turns to participate in a pseudomarket for the remaining objects. We show that the set of all SP-equilibrium random assignments gener-ated by every possible ordered partition coincides with the ex-ante weak core. Moreover, if we \u85x priority groups and individual budget limits, the resulting SP-equilibrium as-signments are generically ex-ante Pareto-optimal