Social media, mental health, and political polarization

Is Facebook bad for you? Better study says yes

Richard Hanania has a nice post: How I Changed My Mind on Social Media and Teen Depression. He looked into the trends of mental health problems and whether this could be attributed to social media use. I reviewed that evidence about one year ago, coming up with a maybe a bit bad, but I apparently missed one very good study from 2020:

• Allcott, H., Braghieri, L., Eichmeyer, S., & Gentzkow, M. (2020). The welfare effects of social media. American Economic Review, 110(3), 629-676.

The rise of social media has provoked both optimism about potential societal benefits and concern about harms such as addiction, depression, and political polarization. In a randomized experiment, we find that deactivating Facebook for the four weeks before the 2018 US midterm election (i) reduced online activity, while increasing offline activities such as watching TV alone and socializing with family and friends; (ii) reduced both factual news knowledge and political polarization; (iii) increased subjective well-being; and (iv) caused a large persistent reduction in post-experiment Facebook use. Deactivation reduced post-experiment valuations of Facebook, suggesting that traditional metrics may overstate consumer surplus

First, their sample size is huge: 2,700 people. They paid them to use less Facebook and they did:

Naturally, there's some substitution effect where they just use something else:

TV use goes up a bit, social interaction doesn't change much. Is TV much better? Maybe? We had TV for several decades and it doesn't seem particularly associated with bad mental health. Here's their effects on mental health:

The error bars are pretty close to 0, so even 2700 people wasn't enough to see an effect for them. But overall their well-being index increase by about 0.1 d, which is not too shabby for essentially a free intervention of self-control.

The most interesting finding is that using Facebook less makes you less leftist:

No much effect on Republicans but maybe some. Democrats who weren't exposed to Facebook for 4 weeks moved somewhat towards the center, or the Facebook group moved further to the left. Seems like the conservative political pundits talking about Facebook indoctrination were right to some extent.

Insofar as social media are concerned, Facebook probably isn't the worst. I would guess that Tiktok/Youtube rolls are worse. They are even further down the dumbed-down ADHD approach to entertainment. Facebook is mostly a boomer thing these days, aside from the odd rationalist discussion group. I hardly use it, and I don't encourage anyone to start.