Republican media is better at persuasion than the Democrats

Terrifying.

“Fox is substantially better at influencing Democrats than MSNBC is at influencing Republicans," the authors find. While most Fox viewers are Republican, a sizeable minority aren't, and they're particularly suggestible to the channel's influence. In 2000, they estimate that 58 percent of Fox viewers who were initially Democrats changed to supporting the Republican candidate by the end of the election cycle; in 2004, the persuasion rate was 27 percent, and 28 percent in 2008. MSNBC, by contrast, only persuaded 8 percent of initial Republicans to vote Democratic in the 2008 cycle.

These are big effects, with major societal implications. The authors find that the Fox News effect translates into a 0.46 percentage point boost to the GOP vote share in the 2000 presidential race, a 3.59-point boost in 2004, and a 6.34-point boost in 2008; the boost increases as the channel's viewership grew. This effect alone is large enough, they argue, to explain all the polarization in the US public's political views from 2000 to 2008.

It’s really hard to estimate the effects of media outlets on individuals’ behaviour, as media consumption is a two-way street. Yes, media can change peoples’ opinions and behaviour, but people also choose to consume particular media because it aligns with their opinions and affirms stuff they’re doing already. So figuring out that a given media outlet is changing viewers’ minds, rather than merely reflecting their viewpoints back to them, is tricky. But Martin and Yurukoglu figured out an ingenious way around that problem: channel ordering.

It turns out that more people watch Fox News when it has a lower channel number. Fox News’s average channel number is around 38 to 41 (depending on which of Martin and Yurukoglu’s samples you're looking at) and lowering the channel number to 19 to 23 or thereabouts causes viewers to watch 2.5 more minutes per week of Fox News, on average. In practice, that could translate into no effect on most people and a bigger effect (like, an hour more viewing per week) among a minority of cable subscribers — 2.5 minutes is just the overall figure.

What’s more, it doesn't appear that cable or satellite TV providers make channel position decisions based on local politics; they don't lower Fox News' channel number in conservative towns or countries or raise it in liberal cities. So people in areas where Fox News has a low channel number watch more of the channel for reasons that are basically random, and unrelated to the viewer’s personal politics.

[I haven't ever watched MSNBC, but I have watched Fox and I don't understand why anyone would watch it for more than about 5 minutes at a stretch.]

https://www.vox.com/policy-and-politics/2017/9/8/16263710/fox-news-presidential-vote-study