Media Slant is Contagious
Philine Widmer, Clémentine Abed Meraim, Sergio Galletta, Elliott Ash
TL;DR
This paper investigates whether media slant is contagious by estimating the causal impact of local Fox News Channel exposure on the Republican slant of local newspapers, using channel-position as an exogenous instrument for viewership. It develops a text-based slant measure by training a penalized multinomial model on Congressional speeches to score local newspaper content, then applies this model to 2005–2008 newspaper articles matched to county-level Nielsen data. The main finding is that higher local FNC exposure makes local newspapers more right-leaning, with a local average treatment effect of about $0.5$ SD per $1$ SD increase in viewership, and the timing and geography of effects support a persuasion mechanism rather than pure content borrowing or competitive shifts. The analysis demonstrates that cross-media bias can propagate through attention channels, implying that national partisan messaging can reshape local discourse and potentially amplify political polarization. These results highlight important implications for media diversity and regulatory considerations regarding spillovers between media outlets.
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.