A seller is selling multiple objects to a set of agents, who can buy at most one object. Each agent's preference over (object, payment) pairs need not be quasilinear. The seller considers the following desiderata for her mechanism, which she terms desirable: (1) strategy-proofness, (2) ex-post...

Goods and services---public housing, medical appointments, schools---are often allocated to individuals who rank them similarly but differ in their preference intensities. We characterize optimal allocation rules when individual preferences are known and when they are not. Several insights...