Media Slant is Contagious

2022-02-15

AI Summary

This paper investigates whether the expansion of Fox News Channel (FNC) from 1995 to 2008 induced a rightward shift in the political slant of local newspapers—termed “media bias contagion.” Employing an instrumental variable approach, it constructs newspaper slant at the micro-level using word embeddings trained on congressional speech corpora and instruments FNC viewership via geographic availability. The analysis identifies, for the first time, causal effects of national media on local news content. Results show that a one-standard-deviation increase in FNC viewership leads to a statistically significant rightward shift in local newspapers’ political coverage, with a 2–4 year lag consistent with evolving local voter behavior. The mechanism operates through FNC’s reinforcement of local conservative preferences, which subsequently reshapes editorial decision-making. The study uncovers a novel channel—national media altering local political ecosystems—to explain bias diffusion, offering both methodological innovation in causal identification and new empirical insights into the dynamic mechanisms of media influence.

Abstract

This paper examines the diffusion of media slant. We document the influence of Fox News Channel (FNC) on the partisan slant of local newspapers in the U.S. over the years 1995-2008. We measure the political slant of local newspapers by scaling the news article texts to Republicans' and Democrats' speeches in Congress. Using channel positioning as an instrument for viewership, we find that higher FNC viewership causes local newspapers to adopt more right-wing slant. The effect emerges gradually, only several years after FNC's introduction, mirroring the channel's growing influence on voting behavior. A main driver of the shift in newspaper slant appears to be a change in local political preferences.

Problem

• Examines media slant diffusion
• Measures FNC's influence on newspapers
• Links viewership to right-wing slant

Innovation

• Analyzes media slant diffusion
• Uses Congress speeches scaling
• Employs channel positioning instrument