Bias in Cable News: Real Effects and Polarization

We jointly measure the persuasive effects of slanted news and tastes for like-minded news. The key ingredient is using channel positions as exogenous shifters of cable news viewership. Local cable positions affect viewership by cable subscribers. They do not correlate with viewership by local satellite subscribers, who are observably similar to cable subscribers. We estimate a model of voters who select into watching slanted news, and whose ideologies evolve as a result. We estimate that Fox News increases the likelihood of voting Republican by 0.9 points among viewers induced into watching four additional minutes per week by differential channel positions.