A principal needs to elicit the true value of an object she owns from an agent who has a unique ability to compute this information. The principal cannot verify the correctness of the information, so she must incentivize the agent to report truthfully. Previous works coped with this unverifiability by employing two or more information agents and awarding them according to the correlation between their reports. We show that, in a common value setting, the principal can elicit the true information even from a single information agent, and even when computing the value is costly for the agent. Moreover, the principal’s expense is only slightly higher than the cost of computing the value. For this purpose we provide three alternative mechanisms, all providing the same above guarantee, highlighting the advantages and disadvantages in each. Extensions of the basic mechanism include adaptations for cases such as when the principal and the agent value the object differently, when the object is divisible and when the agent’s cost of computation is unknown. Finally, we deal with the case where delivering the information to the principal incurs a cost. Here we show that substantial savings can be obtained in a multi-object setting.

中文翻译：

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从单个代理商获取昂贵的无法验证的估值

委托人需要从具有独特能力来计算此信息的代理中得出她拥有的对象的真实价值。委托人无法验证信息的正确性，因此她必须激励代理人如实汇报。先前的工作通过雇用两个或更多信息代理并根据他们的报告之间的相关性授予他们来解决这种不可验证性。我们证明，在一个通用值设置中，委托人甚至可以从单个信息代理中获取真实信息，甚至在计算该值对于代理而言成本很高时也是如此。此外，委托人的费用仅略高于计算价值的费用。为此，我们提供了三种替代机制，所有机制均提供上述相同的保证，突出了每种机制的优缺点。基本机制的扩展包括针对情况的适应，例如当委托人和代理对对象的价值不同，当对象是可分割的以及代理的计算成本未知时。最后，我们处理将信息传递给委托人会产生成本的情况。在这里，我们表明在多对象设置中可以节省大量资金。