Optimally Curating an Event

We study the optimal design of a self-financing event, a problem that requires balancing the recruitment of costly, positive-value participants with revenue-generating agents who may impose negative values on the event. We introduce a novel two-sided mechanism design framework with plus agents equipped with private costs and positive impact, and minus agents with private values and negative impact upon inclusion in the event, to maximize the overall quality of the event under a budget-balanced (BB) constraint so that the designer does not run a deficit. We conduct a comprehensive study on the theory of optimal event curation on various utility functions. For an additive utility setting, we fully characterize the optimal incentive-compatible Bayesian mechanism under both the ex-ante and ex-post BB constraint. For submodular utility, we propose an ex-ante BB mechanism to achieve constant-factor approximation to the first-best outcome. We complement our results by investigating prior-free mechanism and conducting comparative statics.