Original
Why are surveys struggling to estimate vote shares?
Abstract
Abstract Polling in the 2020 US presidential elections significantly underestimated Trump support, calling into question the accuracy of all political surveys. Although many have speculated that this bias is due to Trump supporters refusing to respond to surveys, we have previously lacked the data to directly evaluate this theory. This paper leverages the rich and unique set of data collected alongside the 2020 American National Election Studies (ANES) to identify and quantify sources of error using the Total Survey Error framework. We document evidence of nonignorable unit nonresponse; that is, Trump supporters were less likely to respond and less likely to complete the 2020 ANES if they did respond. We are also able to rule out other potential sources of error. Our analyses identify a fundamental threat to political surveys, and careful diagnosis and quantification of the bias is critical for informing corrections and future survey design.
中文
为何调查难以估计选票份额？
摘要
摘要：2020年美国总统选举中的民调显著低估了特朗普的支持率，使人们对所有政治调查的准确性产生质疑。尽管许多人推测这种偏差是由于特朗普支持者拒绝回应调查所致，但此前我们缺乏直接评估这一理论的数据。本文利用与2020年美国全国选举研究（ANES）一同收集的丰富而独特的数据，采用总调查误差框架来识别并量化误差来源。我们记录了不可忽略的单位无应答的证据；也就是说，特朗普支持者更不可能回应，而即便他们回应，也更不可能完成2020年ANES。我们还能够排除其他潜在的误差来源。我们的分析揭示了政治调查面临的一项根本性威胁，而审慎诊断和量化这种偏差对于为校正和未来调查设计提供依据至关重要。
关键词
民意调查、选票份额、无应答偏差、总调查误差、2020年美国总统选举、美国全国选举研究、特朗普支持者、调查设计