Collusion through Coordination of Announcements
研究卖方如何通过协调标价（或附加费）来有效合谋，同时保留设定最终价格的自由；标价作为成本信息的廉价谈话，影响买方的采购拍卖决策，导致超竞争价格并可能提高社会福利。
A theory is developed to explain how sellers can effectively collude by coordinating on list prices (or surcharges), while leaving sellers to set their final prices. List prices are interpreted to be cheap talk announcements about cost information unknown to buyers. Buyers use those announcements to decide whom to invite to their procurement auction and the reserve price to set. By coordinating on a high list price to signal high cost, sellers produce supracompetitive prices by inducing buyers to be less aggressive, as reflected in a higher reserve price. We show that collusion can raise social welfare.