Lotteries are a common way to resolve ties in assignment mechanisms that ration resources. We consider a model with a continuum of agents and a finite set of re- sources with heterogeneous qualities, where the agents’ preferences are generated from a multinomial-logit (MNL) model based on the...

As multi-hospital kidney exchange has grown, the set of players has grown from patients and surgeons to include hospitals. Hospitals can choose to enroll only their hard-to-match patient-donor pairs, while conducting easily-arranged exchanges internally. This behavior has already been observed....