Red News, Blue News: Political Consequences of News Bias.

摘要

The recent expansion of media outlets has produced an unexplored side effect: the rise of news sources with a partisan slant. While others have documented partisan segmentation within the news audience, important questions remain. Why do people choose to consume biased news and what are the political consequences of this decision? I provide some of the first answers to these important questions, focusing critically on the cognitive mechanisms driving news choice and its real-world effects. I argue that the effects of biased news are best understood by conceptualizing of bias as a "cognitive subsidy," which reduces uncertainty, lowers information costs, and provides consistent ideological constraint for viewers across issue domains. Paradoxically, I find selection into biased news audiences is driven by a desire for unbiased news and document experimental evidence supporting a congenial media effect, where information consistent with existing beliefs is seen as more credible and less biased. Using the debate over President Barack Obama's health care reform efforts as a case study, I explore how reliance on partisan news affects the public distribution of political information, finding both pervasive and persuasive partisan bias. Merging individual-level survey data with data on local cable providers, I examine the introduction of the Fox News Channel into U.S. media markets during the 2002 U.S. congressional elections, finding that access to Fox News increased political participation rates. I expand this approach to the 2004 presidential election, using Fox News availability as an instrument to estimate the direct effect of exposure to bias on political participation, finding a consistent positive effect. In particular, I find that the participatory effects of bias are stronger for less educated individuals. In sum, this dissertation offers some of the first theoretical and empirical insights into the political consequences of biased news. As with other communication technologies that have developed over time, biased news is a double-edged sword with obvious downsides for public competence but also surprising upsides.