期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2022
卷号：119
期号：32
DOI：10.1073/pnas.2202197119
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Ideological media bias is increasingly central to the study of politics. Yet, past literature often assumes that the ideological bias of any outlet, at least in the short term, is static and exogenous to the political process. We challenge this assumption. We use longitudinal data from the Stanford Cable News Analyzer (2010 to 2021), which reports the screen time of various political actors on cable news, and quantify the partisan leaning of those actors using their past campaign donation behavior. Using one instantiation of media bias—the mean ideology of political actors on a channel, i.e., visibility bias—we examine weekly, within-day, and program-level estimates of media bias. We find that media bias is highly dynamic even in the short term and that the heightened polarization between TV channels over time was mostly driven by the prime-time shows.
