Several election districts in the US have recently moved to ranked-choice voting (RCV) to decide the results of local elections. RCV allows voters to rank their choices, and the results are computed in rounds, eliminating one candidate at a time. RCV ensures fairer elections and has been shown to increase elected representation of women and people of color. A main drawback of RCV is that the round-by-round process requires all the ballots to be tallied before the results of an election can be calculated. With increasingly large portions of ballots coming from absentee voters, RCV election outcomes are not always apparent on election night, and can take several weeks to be published, leading to a loss of trust in the electoral process from the public. In this paper, we present an algorithm for efficiently computing possible winners of RCV elections from partially known ballots and evaluate it on data from the recent New York City Primary elections. We show that our techniques allow to significantly narrow down the field of possible election winners, and in some case identify the winner as soon as election night despite a number of yet-unaccounted absentee ballots, providing more transparency in the electoral process.
翻译:美国的几个选区最近已经转向了等级投票,以决定地方选举的结果。市选民选举允许选民对选举结果进行排名,选举结果可以分几轮计算,一次淘汰一名候选人。市选民选举确保了更公平的选举,并显示选举增加了妇女和有色人种的当选代表比例。州选民选举的主要缺点是,轮投票过程要求在计算选举结果之前对所有选票进行清点。随着缺席选民的选票数量越来越多,区选民选举结果并不总是在选举之夜显露出来,而且选举结果可能要花几个星期才能公布,从而导致公众对选举进程失去信任。在本文件中,我们提出了一种算法,以便从部分已知选票中高效计算RCV选举可能的获胜者,并根据最近纽约市初级选举的数据对它进行评估。我们表明,我们的技术可以大大缩小可能当选者的范围,在某些情况下,在选举之夜,尽管有一些尚未记账的缺席选票,但选举过程的透明度更高。