Coalition For Gsp

Group strategyproofness (GSP), also called coalitional strategyproofness, is a property of mechanisms and voting rules in social choice theory and mechanism design. A mechanism is group-strategyproof if no coalition of agents can all gain by jointly misreporting their private information: there is no group of agents and no joint deviation from truthful reporting that makes at least one member of the group strictly better off without making any other member of the group worse off. via Wikipedia ↗