论文标题
同步迭代投票中的周期：一般鲁棒性和批准投票中的例子
Cycles in synchronous iterative voting: general robustness and examples in Approval Voting
论文作者
论文摘要
我们考虑同步的迭代投票，在该迭代中，选民有机会根据以前的集体选择中得出的结果来战略性地选择他们的选票。我们提出了两种设置，用于同步迭代投票，一种具有离散状态的古典风味之一，以及更一般的连续空间设置扩展了第一个。我们为不依靠抢七规则的周期提供了一般的鲁棒性结果，这表明它们持续到了足够小的选民行为扰动下。然后，我们给出了批准投票的例子，该选举人采用简单，真诚和一致的启发式法案（即拉斯利尔的领导者统治或对其进行修改），导致结果有不良成果的周期，或者不选出现有的condorcet赢家，或者可能由选民的主要选民排名最后。使用鲁棒性结果，即使只有（足够大的）选民在每次迭代时更新选票的选择，也可以在其他投票方法中完成这些结果，包括其他投票方法，包括满足condorcet标准的排名；一项关于表现出不良周期的偏好曲线稀有性的硅硅实验研究；以及表现出混乱行为的例子。
We consider synchronous iterative voting, where voters are given the opportunity to strategically choose their ballots depending on the outcome deduced from the previous collective choices.We propose two settings for synchronous iterative voting, one of classical flavor with a discrete space of states, and a more general continuous-space setting extending the first one. We give a general robustness result for cycles not relying on a tie-breaking rule, showing that they persist under small enough perturbations of the behavior of voters. Then we give examples in Approval Voting of electorates applying simple, sincere and consistent heuristics (namely Laslier's Leader Rule or a modification of it) leading to cycles with bad outcomes, either not electing an existing Condorcet winner, or possibly electing a candidate ranked last by a majority of voters. Using the robustness result, it follows that those "bad cycles" persist even if only a (large enough) fraction of the electorate updates its choice of ballot at each iteration.We complete these results with examples in other voting methods, including ranking methods satisfying the Condorcet criterion; an in silico experimental study of the rarity of preference profiles exhibiting bad cycles; and an example exhibiting chaotic behavior.
