Ex-Ante Design of Persuasion Games

How does receiver commitment affect incentives for information revelation in Bayesian persuasion? We study many-sender persuasion games where a single receiver commits to a posterior-dependent action profile, or allocation, before senders design the informational environment. We develop a novel revelation-like principle for ex-ante mechanism design settings where sender reports are Blackwell experiments and use it to characterize the set of implementable allocations in our model. We show global incentive constraints are pinned down by "worst-case" punishments at finitely many posterior beliefs, whose values are independent of the allocation. Moreover, the receiver will generically benefit from the ability to randomize over deterministic outcomes when solving for the constrained optimal allocation, in contrast to standard mechanism design models. Finally, we apply our results to analyze efficiency in multi-good allocation problems, full surplus extraction in auctions with allocation externalities, and optimal audit design, highlighting the role that monotone mechanisms play in these settings.