多参数隐式支付机制
Multi-parameter Mechanisms with Implicit Payment Computation
摘要：
在本文中，我们表明，支付计算基本上不存在任何障碍，在设计真实的机制，即使是多参数域，甚至当我们只能调用一次分配规则。我们提出了一个一般的减少，采取任何分配规则，满足“循环单调性”（一个已知的必要和充分条件的真实性），并将其转换为一个真实的机制，使用一个单一的调用分配规则，任意小的损失，预期的社会福利。一个突出的例子是多参数设置，其中一个分配规则只能被调用一次出现在赞助搜索拍卖。这些是多参数域，当每个广告商有多个可能的广告，他可以显示，每一个具有不同的价值，每次点击。此外，该机制通常不具有点击实现或点击率（CTR）的完整知识;它只能调用分配规则一次并观察所呈现的广告的点击信息。%未知。在消极的一面，我们表明，分配是真实的任何实现基本上不能依赖于出价，因此不能做得比随机选择一个代理。然后，我们考虑一个放松的真实性要求，只有在预期的CTR。即使对于宽松的版本，取得任何进展都是具有挑战性的，因为用于构建真实机制的标准技术（如使用VCG或MIDR分配规则）不能在此设置中使用。我们设计了一个具有非平凡性能的分配规则，并直接证明了它是循环单调的，因此它可以用来创建一个真实的机制，使用我们的一般约简。
英文摘要：
In this paper we show that payment computation essentially does not present any obstacle in designing truthful mechanisms, even for multi-parameter domains, and even when we can only call the allocation rule once. We present a general reduction that takes any allocation rule which satisfies "cyclic monotonicity" (a known necessary and sufficient condition for truthfulness) and converts it to a truthful mechanism using a single call to the allocation rule, with arbitrarily small loss to the expected social welfare. A prominent example for a multi-parameter setting in which an allocation rule can only be called once arises in sponsored search auctions. These are multi-parameter domains when each advertiser has multiple possible ads he may display, each with a different value per click. Moreover, the mechanism typically does not have complete knowledge of the click-realization or the click-through rates (CTRs); it can only call the allocation rule a single time and observe the click information for ads that were presented. % are not known. On the negative side, we show that an allocation that is truthful for any realization essentially cannot depend on the bids, and hence cannot do better than random selection for one agent. We then consider a relaxed requirement of truthfulness, only in expectation over the CTRs. Even for that relaxed version, making any progress is challenging as standard techniques for construction of truthful mechanisms (as using VCG or an MIDR allocation rule) cannot be used in this setting. We design an allocation rule with non-trivial performance and directly prove it is cyclic-monotone, and thus it can be used to create a truthful mechanism using our general reduction.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
