Approximate Strategyproofness

The standard approach of mechanism design theory insists on equilibrium behavior by participants. This assumption is captured by imposing incentive constraints on the design space. But in bridging from theory to practice, it often becomes necessary to relax incentive constraints in order to allow tradeo↵s with other desirable properties. This paper surveys a number of different options that can be adopted in relaxing incentive constraints, providing a current view of the state-of-the-art.