We study market interactions in which buyers are allowed to credibly reveal partial information about their types to the seller. Previous recent work has studied the special case of one buyer and one good, showing that such communication can simultaneously improve social welfare and ex ante buyer utility. However, with multiple buyers, we find that the buyer-optimal signalling schemes from the one-buyer case are actually harmful to buyer welfare. Moreover, we prove several impossibility results showing that, with either multiple i.i.d. buyers or multiple i.i.d. goods, maximizing buyer utility can be at odds with social efficiency, which is surprising in contrast with the one-buyer, one-good case. Finally, we investigate the computational tractability of implementing desirable equilibrium outcomes. We find that, even with one buyer and one good, optimizing buyer utility is generally NP-hard but tractable in a practical restricted setting.

翻译：我们研究市场互动,允许买方向卖方可靠地披露有关其类型部分信息的市场互动。最近的工作研究了一个买方和一个货物的特殊案例,表明这种通信可以同时改善社会福利和前买方效用。然而,与多个买方相比,我们发现一买方案件中买方最佳信号计划实际上有害于买方福利。此外,我们证明若干不可能的结果表明,如果是多个买方或多个货物,最大限度发挥买方效用可能与社会效率不符,这与单买方一个好案例不同,令人惊讶。最后,我们调查了实施适当平衡结果的计算可及性。我们发现,即使有一个买方和一个好买方,优化买方效用一般是硬的,但在实际的限制环境下是易行的。