Tyler Cowen links today to a paper suggesting that knowledge of a person’s social network is more important than specific knowledge about the person herself. For some reason I clicked. It turns out the paper is written by a bunch of math and physics types and includes stuff like this:

The predictive information contained within a user’s text can be characterized by three related quantities, the entropy rate h, the perplexity 2h, and the predictability Π….We applied a nonparametric entropy estimator that incorporates the full sequence structure of the text. This estimator has been proved to converge asymptotically to the true entropy rate for stationary processes and has been applied to human mobility data.

In other words, it’s pretty much incomprehensible. However, it’s incomprehensible in a way that appeals to me, so I read it. I’ve got an hour or two to kill right now, so why not?

The authors are looking at something very specific when they talk about “predictability.” They analyzed the Twitter feeds of about a thousand people, and for each tweet they tried to predict what the next word in the tweet would be given the person’s past writing. Their question is, if you look solely at the writing of the person’s friends on Twitter, how accurately can you predict what they’re going to say? It turns out that this depends on how many friends you look at, with predictability topping out at around 15 friends.

So how good is predictability when you look at 15 friends? Pretty damn good:

At around nine friends, the friends were better predictors than the person’s own past writings, represented by the black line labeled Π (ego). At 15 friends, the friends are considerably better, and adding the person’s own past writing increases predictability by only 3.2 percentage points. The authors point out what this means:

This may have distinct implications for privacy: if an individual forgoes using a social media platform or deletes her account, yet her social ties remain, then that platform owner potentially possesses 95.1% of the achievable predictive accuracy of the future activities of that individual.

In a nutshell, this means you can delete your Facebook account all you want, and it barely matters. If I already know who your friends are, I have a continuing stream of information about what things you’re likely to buy and which candidates you’re likely to vote for.

This paper, obviously, uses a very restricted meaning of “predictability.” Nonetheless, it’s suggestive that other kinds of predictability may be accessible through your friends too. If your friends like guns or beauty supplies, there’s a pretty good chance that you do too. Likewise, if some hot new fashion hits the stores and your friends all hate it, you probably hate it too. And if your friends seem to be undecided about a political candidate and are potentially persuadable with a specific message? Well, you probably are too, even if you insist that you are truly a unique snowflake uninfluenced by fads and peer pressure.

In other words, we are all doomed. Unless you can convince all your friends to abandon social media, it barely matters if you yourself do. Big Brother is still watching.

WE'LL BE BLUNT

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WE'LL BE BLUNT

It is astonishingly hard keeping a newsroom afloat these days, and we need to raise \$253,000 in online donations quickly, by October 7.

The short of it: Last year, we had to cut \$1 million from our budget so we could have any chance of breaking even by the time our fiscal year ended in June. And despite a huge rally from so many of you leading up to the deadline, we still came up a bit short on the whole. We can’t let that happen again. We have no wiggle room to begin with, and now we have a hole to dig out of.

Readers also told us to just give it to you straight when we need to ask for your support, and seeing how matter-of-factly explaining our inner workings, our challenges and finances, can bring more of you in has been a real silver lining. So our online membership lead, Brian, lays it all out for you in his personal, insider account (that literally puts his skin in the game!) of how urgent things are right now.

The upshot: Being able to rally \$253,000 in donations over these next few weeks is vitally important simply because it is the number that keeps us right on track, helping make sure we don't end up with a bigger gap than can be filled again, helping us avoid any significant (and knowable) cash-flow crunches for now. We used to be more nonchalant about coming up short this time of year, thinking we can make it by the time June rolls around. Not anymore.

Because the in-depth journalism on underreported beats and unique perspectives on the daily news you turn to Mother Jones for is only possible because readers fund us. Corporations and powerful people with deep pockets will never sustain the type of journalism we exist to do. The only investors who won’t let independent, investigative journalism down are the people who actually care about its future—you.

And we need readers to show up for us big time—again.

Getting just 10 percent of the people who care enough about our work to be reading this blurb to part with a few bucks would be utterly transformative for us, and that's very much what we need to keep charging hard in this financially uncertain, high-stakes year.

If you can right now, please support the journalism you get from Mother Jones with a donation at whatever amount works for you. And please do it now, before you move on to whatever you're about to do next and think maybe you'll get to it later, because every gift matters and we really need to see a strong response if we're going to raise the \$253,000 we need in less than three weeks.