A characterization of the Extended Serial Correspondence∗

We study the problem of assigning objects to a group of agents, when each agent reports ordinal preferences over the objects. We allow for indifference among objects. We focus on probabilistic methods, in particular, the extended serial correspondence, introduced by Katta and Sethuraman (2006). Our main result is a characterization of the extended serial correspondence in welfare terms by means of stochastic dominance efficiency, stochastic dominance no-envy and “bounded invariance,” an axiom we adapt from Bogomolnaia and Heo (2011). We also prove that an assignment matrix is selected by the extended serial correspondence if and only if it satisfies “non-wastefulness” and “ordinal fairness,” which we adapt from Kesten et al. (2011). JEL classification: C70, D61, D63.