  We study the problem of allocating multiple objects to agents without
transferable utilities, where each agent may receive more than one object
according to a quota. Under lexicographic preferences, we characterize the set
of strategyproof, non-bossy, and neutral quota mechanisms and show that under a
mild Pareto efficiency condition, serial dictatorship quota mechanisms are the
only mechanisms satisfying these properties. Dropping the neutrality
requirement, this class of quota mechanisms further expands to sequential
dictatorship quota mechanisms. We then extend quota mechanisms to randomized
settings, and show that the random serial dictatorship quota mechanisms (RSDQ)
are envyfree, strategyproof, and ex post efficient for any number of agents and
objects and any quota system, proving that the well-studied Random Serial
Dictatorship (RSD) satisfies envyfreeness when preferences are lexicographic.
