We prove that group strategy-proofness and strategy-proofness are equivalent requirements on stable mechanisms in priority-based resource allocation problems with multi-unit demand. The result extends to the model with contracts

We study the implementation of social choice rules in environments with externalities. We prove the impossibility of implementing efficient and α-individually rational rules in dominant strategies. We prove that the α-core is implementable in Nash equilibrium under mild restrictions and it is...

We study the existence of group strategy-proof stable rules in many-to-many matching markets under responsiveness of agents' preferences. We show that when firms have acyclical preferences over workers the set of stable matchings is a singleton, and the worker-optimal stable mechanism is a...