Group-Strategy-Proofness In Private-Good Economies: Revisited
We provide sufficient conditions for a strategy-proof allocation rule to be weakly group-strategy-proof. Our results are applicable to a wide variety of allocation rules in models with private goods, including models of house allocation, matching, single-object auctions, cost sharing, and task division. Our properties are independent of those used in Barbera, Berga and Moreno (AER, 2016) to achieve the same result. However, we show that we cover all the rules they consider, and we additionally identify a well-known family of (generalised priority) rules for which the result is only covered by our properties. Our properties are based on a new interpretation of `bossiness' that provides a fresh insight into bossy allocation rules.