A random assignment is robust ex-post Pareto efficient whenever for any of its lottery decomposition, each deterministic assignment in its support is Pareto efficient. We show that ordinal efficiency implies robust ex-post Pareto efficiency while the reverse does not hold. We know that...

We introduce ex-ante Pareto efficiency, which is a slightly weaker notion of efficiency than ex-post Pareto efficiency. We strengthen the impossibility between ex-post Pareto efficiency, strategyproofness, and envy-freeness in the random assignment problem and show that it prevails if ex-post...

We introduce ex-ante Pareto efficiency, which is a slightly weaker notion of efficiency than ex-post Pareto efficiency. We strengthen the impossibility between ex-post Pareto efficiency, strategyproofness, and envy-freeness in the random assignment problem and show that it prevails if ex-post...