论文标题
委派潘多拉的盒子
Delegated Pandora's box
论文作者
论文摘要
在委派问题中,委托人没有完成特定任务所需的资源,因此他们将任务委派给了一个不受信任的代理,其利益可能与自己的利益不同。鉴于任何此类问题和机制空间的家庭都可以选择,因此,当他们自行解决问题时,代表团差距是校长最佳效用的最佳比例。在这项工作中,我们考虑了广义潘多拉盒问题的委托差距,搜索问题在其中搜索解决方案会产生已知成本和解决方案受到一些向下关闭的约束的限制。首先,我们表明,当所有随机变量都具有二进制支持时,存在一种特殊情况,其中存在用于矩阵约束的恒定因素委托差距。但是,即使是简单的非二元实例,也没有恒定因素委托差距。解决这种不可能的情况,我们考虑了两个变体:自由球员模型,其中代理商不支付探测要素的成本和折现成本近似值,在这种情况下,我们打折所有费用,并旨在使折现因子和授权差距的双刻板标准近似。我们表明,自由球员模型中存在恒定因素代表团差距,其折现成本近似值具有某些向下闭合约束和恒定折现因子。但是,仅在任何一个变体下都无法实现恒定的委托差距。最后,我们考虑了另一个称为共享成本模型的变体,在该模型中,主体可以选择在委派搜索问题之前如何在代理商和代理之间共享成本。我们表明,共享成本模型具有某些向下封闭约束的恒定因素委托差距。
In delegation problems, a principal does not have the resources necessary to complete a particular task, so they delegate the task to an untrusted agent whose interests may differ from their own. Given any family of such problems and space of mechanisms for the principal to choose from, the delegation gap is the worst-case ratio of the principal's optimal utility when they delegate versus their optimal utility when solving the problem on their own. In this work, we consider the delegation gap of the generalized Pandora's box problem, a search problem in which searching for solutions incurs known costs and solutions are restricted by some downward-closed constraint. First, we show that there is a special case when all random variables have binary support for which there exist constant-factor delegation gaps for matroid constraints. However, there is no constant-factor delegation gap for even simple non-binary instances of the problem. Getting around this impossibility, we consider two variants: the free-agent model, in which the agent doesn't pay the cost of probing elements, and discounted-cost approximations, in which we discount all costs and aim for a bicriteria approximation of the discount factor and delegation gap. We show that there are constant-factor delegation gaps in the free-agent model with discounted-cost approximations for certain downward closed constraints and constant discount factors. However, constant delegation gaps can not be achieved under either variant alone. Finally, we consider another variant called the shared-cost model, in which the principal can choose how costs will be shared between them and the agent before delegating the search problem. We show that the shared-cost model exhibits a constant-factor delegation gap for certain downward closed constraints.