标题： 争夺关注——美国广播电台对选举和政治极化的影响 显示英文标题

标题： Competing for Attention -- The Effect of Talk Radio on Elections and Political Polarization in the US

摘要： 本文研究了广播谈话节目，特别是拉什·林博节目对美国选举结果和态度极化的影响。我们提出了一种新的识别策略，将每个县的广播空间视为一个市场，其中多个电台竞争听众的关注。我们的竞争衡量标准是广播频率的空间赫芬达尔-赫希曼指数（HHI）。为了解决内生性问题，我们利用县内意外频率重叠带来的竞争变化，条件是整体广播频率竞争水平。我们发现，接触拉什·林博节目的县在2016年和2020年美国总统大选中，唐纳德·特朗普的得票率系统性地更高。将我们的县一级拉什·林博节目接触度测量与个体调查数据相结合，揭示出在接触度较高的县中，自认为共和党的人表达更保守的政治观点，而在这些县中自认为民主党的人则表达更温和的政治观点。综合来看，这些发现提供了关于当代广播谈话节目对政治成果影响的一些最早见解，涵盖了总体和个体层面。 显示英文摘要

摘要： This paper studies the effects of talk radio, specifically the Rush Limbaugh Show, on electoral outcomes and attitude polarization in the U.S. We propose a novel identification strategy that considers the radio space in each county as a market where multiple stations are competing for listeners' attention. Our measure of competition is a spatial Herfindahl-Hirschman Index (HHI) in radio frequencies. To address endogeneity concerns, we exploit the variation in competition based on accidental frequency overlaps in a county, conditional on the overall level of radio frequency competition. We find that counties with higher exposure to the Rush Limbaugh Show have a systematically higher vote share for Donald Trump in the 2016 and 2020 U.S. presidential elections. Combining our county-level Rush Limbaugh Show exposure measure with individual survey data reveals that self-identifying Republicans in counties with higher exposure to the Show express more conservative political views, while self-identifying Democrats in these same counties express more moderate political views. Taken together, these findings provide some of the first insights on the effects of contemporary talk radio on political outcomes, both at the aggregate and individual level.