经济学人 | 美国的政治极化真的在加剧吗?

文章来源：经济学人2021年10月5日

OVER THE weekend wonks flocked to Seattle for the annual meeting of the American Political Science Association. Among other things, they discussed how political divisions hamper the fight against covid-19. America now lags behind much of the rich world in its vaccine rollout, in part because of the reluctance of some on the right to get jabbed. But the academic debate is not conclusive on the extent to which polarisation is rising; political scientists even disagree on how to define it. How is polarisation measured, and are American voters really growing further apart?

上周末，学者们蜂拥至西雅图参加美国政治科学协会的年会。除其他事项外，他们还在会上讨论了政治分歧如何妨碍抗击新冠疫情的问题。美国目前在疫苗推广方面落后于许多发达国家，部分原因是一些右翼人士不愿接种疫苗。但是学术界对美国两极分化的程度还没有定论；政治学家甚至对如何定义两极分化也存在分歧。如何衡量两极分化？美国选民之间的分歧真的越来越大了吗？

In general, political polarisation is defined as the grouping of people into two extreme positions. The tricky bit is determining which opinions or traits should be used to form those groupings. Polarisation can broadly be categorised two ways, says Lilliana Mason of Johns Hopkins University. The first, “social polarisation”, measures the extent to which a person’s ideology and identity (which includes traits such as race or religion) are associated with their political party. High social polarisation results in increased partisan bias and negative feelings towards supporters of the other party. Nearly 40% of Americans, for example, would be upset if their child married someone who supported a party other than their own. The second category, “issue-position polarisation”, measures the extent to which Americans’ policy preferences reflect extreme positions rather than more moderate ones, irrespective of which party they support.

一般来说，政治极化是指人们被分成两个极端立场。但棘手的是决定哪些观点或特征应该作为分组标准。约翰霍普金斯大学的莉莉安娜·梅森（Lilliana Mason）认为，两极分化大致可以分为两类。第一是社会极化，衡量一个人的意识形态和身份（包括种族或宗教等特征）与他所支持的政党的关联程度。高度的社会极化将导致党派偏见和对另一党派支持者负面情绪的增加。例如，近40%的美国人，如果他们的孩子与支持其他政党的人结婚，他们会感到不安。第二类，议题立场极化，衡量美国人的政策偏好在多大程度上反映了极端立场，而不是较为温和的立场，无论他们支持哪个政党。

 

Depending on which definition you choose, polarisation trends look very different. Social polarisation has increased markedly over the past four decades. Starting after the second world war, and accelerating with the Civil Rights movement, ideological liberals and African Americans shifted towards the Democratic Party while conservatives and white Americans became increasingly Republican, on average (aprocess known as sorting). Democrats have also become more urban, educated, and female at various points since the 1960s. When a person’s social identity is more tied to their party affiliation, partisan bias grows. In 1978, Americans were 27 points colder toward voters from parties other than their own on a 100-point scale. The gap grew to 56 points by 2020. The same cannot be said for issue-position polarisation over the same period. For instance, about half the population took a moderate stance on abortion in 2016, a proportion that has held steady since 1975. Across issues ranging from the armed forces to government spending, the share of the population holding extreme positions has not trended upwards nearly as much as social polarisation, though it has increased somewhat since 2008.

根据所选择的定义的不同，两极分化趋势也会非常不同。在过去四十年里，社会极化明显加剧。从二战后开始，随着民权运动的加速，意识形态上的自由主义者和非裔美国人转向了民主党，而保守派和美国白人则越来越倾向于共和党（这一过程被称为分类）。自20世纪60年代以来，民主党的支持者也逐渐变得更加城市化、受教育程度更高和女性化。当一个人的社会身份与党派联系更紧密时，党派偏见就会增加。1978年，美国人对非自身政党的选民的态度要冷淡27点（区间为0-100点）。到2020年，这一差距扩大到56点。在同一时期，议题立场极化便不如此了。例如，2016年大约一半的人口对堕胎持温和立场，这一比例自1975年以来一直保持稳定。在从军队到政府开支的各种问题上，持有极端立场的人口比例的上升趋势远不及社会两极化，尽管自2008年以来其也有一定程度的增加。

Political scientists have several hypotheses for why partisan sorting has occurred. One explanation is America’s two-party system, which makes it easier to form strong political identities than in countries with several major parties, where holding views that cross party lines is more common. Another is the growth of media outlets that increasingly appeal to partisan viewpoints. Fox News was started in 1996, and social polarisation accelerated sharply in the years afterwards. Political scientists also point to inequality and the growing population of racial minorities in America, but a consensus has yet to emerge.

对于为什么会出现政党选择（party sorting），政治学家有这样几种假设。一种解释是美国的两党制，这使得它比多党制国家更容易形成强烈的政治认同，因为在多党制国家中，持有跨越党派界限的观点更为普遍。另一个解释是，越来越多的媒体开始迎合党派观点。1996年福克斯新闻创办后，美国社会极化急剧加剧。政治学家还指出了美国的不平等和不断增长的少数族裔人口可能也是原因之一，但尚未形成共识。

So has political polarisation grown in America? In one sense, yes. The link between someone’s social identity, political ideology and party appears to be growing stronger. But in terms of their positions on many issues, Americans have not grown to be as extreme. This has led to a paradox of polarisation. Despite agreeing on much, Americans dislike each other more than ever.

那么，美国的政治极化是否加剧了呢？从某种意义上说，是的。一个人的社会身份、政治意识形态和政党之间的联系似乎越来越紧密。但就他们在许多问题上的立场而言，美国人并没有变得那么极端。这导致了两极分化的悖论。尽管在很多问题上意见一致，但美国人却比以往任何时候都不喜欢对方。