Non-Excludable Dynamic Mechanism Design

Proceedings of the 2021 ACM-SIAM Symposium on Discrete Algorithms (SODA), SIAM, pp. 1357-1373


Dynamic mechanism design expands the scope on what type of allocation rules can be implemented and what revenue can be extracted when compared to static mechanisms. The case of excludable environments (i.e. one player can be de-allocated while keeping the allocation of the remaining players intact) is very well understood. The mechanisms in the literature don’t extend to the non-excludable environments. Two prototypical examples of such environments are: (i) public projects, where all players must have the same allocation; and (ii) non-disposable goods, where each item must be allocated to some player. We show a general mechanism that can asymptotically extract the full surplus in such environments. Moreover, we fully characterize which abstract mechanism design environments allow for full surplus extraction in the limit. Our characterization is based on the geometry of achievable utility sets – a convex set characterizing the expected utility profiles that can be implemented in a static mechanism.