Strategic voting, or manipulation, is the process by which a voter misrepresents his preferences in an attempt to elect an outcome that he considers preferable to the outcome under sincere voting. It is generally agreed that manipulation is a negative feature of elections, and much effort has been spent on gauging the vulnerability of voting rules to manipulation. However, the question of why manipulation is actually bad is less commonly asked. One way to measure the effect of manipulation on an outcome is by comparing a numeric measure of social welfare under sincere behaviour to that in the presence of a manipulator. In this paper we conduct numeric experiments to assess the effects of manipulation on social welfare under scoring rules. We find that manipulation is usually negative, and in most cases the optimum rule with a manipulator is different to the one with sincere voters.
翻译:战略投票或操纵是选民歪曲其偏好的程序,以图选出他认为比真诚投票的结果更可取的结果。人们普遍同意操纵是选举的负面特征,在评估投票规则易受操纵的脆弱性方面已经付出了大量努力。然而,为什么操纵实际上是坏的,这个问题不太常见。衡量操纵对结果的影响的方法之一是将真诚行为下的社会福利数量与有操纵者在场的真诚行为中的社会福利数量相比较。在这份文件中,我们进行了数字实验,以评估根据评分规则操纵对社会福利的影响。我们发现操纵通常是负面的,在大多数情况下,操纵者的最佳规则不同于有诚实选民的规则。