A seller has an object for sale and can reach buyers only through intermediaries, who also have privileged information about buyers’ valuations. Intermediaries can either mediate the transaction by buying the object and reselling it–the merchant model–or refer buyers to the seller and...

I study the welfare optimal allocation of a number of identical and indivisible objects to a set of heterogeneous risk-neutral agents under the hypothesis that money is not available. Agents have independent private values, which represent the maximum time that they are willing to wait in line...