Contextually Private Mechanisms
设计者运用动态协议来引出私人信息。协议会产生一组情境隐私侵犯——即所获知的、在给定情境下可能多余的信息。若不存在任何其他协议能在实现同一选择规则的同时，产生该协议所产生侵犯的真子集，则该协议是最大情境隐私的。当选择规则使某些参与人集体地而非个体地成为关键（pivotal）时，便会引发情境隐私侵犯。在拍卖中，出于情境隐私的考量进行设计，需要选择向每个参与人提出的初始问题以及询问各参与人的顺序。对于 k 件物品的维克里（Vickrey）拍卖，递增联合（ascending-join）协议是最大情境隐私的。(JEL D44, D82)
英文原文
A designer employs a dynamic protocol to elicit private information. Protocols produce a set of contextual privacy violations—information learned that may be superfluous given the context. A protocol is maximally contextually private if there is no protocol that produces a proper subset of the violations it produces, while implementing the choice rule. Contextual privacy violations arise when a choice rule makes some agents collectively, but not individually, pivotal. In auctions, designing for contextual privacy requires choosing an initial question posed to each agent and the order for querying agents. Ascending-join protocols are maximally contextually private for k-item Vickrey auctions. (JEL D44, D82)