Facts about (Facebook) friends

1. For the population of the average county, 62.8% of friends live within 100 miles.

2. Over distances of less than 200 miles, the elasticity of friends to distance is about – 2.0, and about – 1.2 for distances greater than 200 miles.

3. Conditional on distance, social connectedness is significantly stronger within state lines.

4. “Counties with a higher social capital index have less geographically concentrated social networks.”

5. Social connectedness predicts trade flows, even after controlling for distance, and it also predicts patent citations.

That is all from a new NBER working paper by Bailey, Cao, Kuchler, Stroebel, and Wong.  Here is an ungated version.


Marriages fail, relationships fail, when they don't have anything in common. How many times have you heard that explanation for a failed marriage or relationship. I've often referred to Robert Wright's thesis (in The Evolution of God) that the spread of Christianity promoted the spread of trade: the common religion provided the trust (social capital) necessary for trade. Christian missionaries are capitalism's frontier explorers. If Wright is right, how will One Belt, One Road succeed? https://www.nytimes.com/2017/07/25/world/middleeast/iran-china-business-ties.html How much do all of these countries have in common? European countries, in contrast, have much in common, yet the European Union has had a fraught existence.

"I’ve often referred to Robert Wright’s thesis (in The Evolution of God) that the spread of Christianity promoted the spread of trade" - they also say the same thing about the diametrical opposite: that military expansion and forced conquest spreads trade, citing Alexander the Great, Cyrus the Great and Ghengis Khan the Great as templars (but not Tamerlane, who apparently was not interested in spreading trade as much as collecting pyramids of heads).

Bonus trivia: a minority of historians feel the Japanese occupation of Korea was actually beneficial, bringing Korea into the modern age, not unlike Admiral Perry's opening of Japan. How did we get on this topic anyway? Dang trolls on this board...

I've long believed a major reason that Taiwan and Korea developed so rapidly in the 1950s and 1960s was the point that at that time their adult populations had been educated under the Japanese school system.

I call reverse causation on 5. People become Facebook friends through commercial relationships.

Yes, though commercial activity also happens through networking and relationships. I doubt there is a basis for claiming clear causation in either direction. (Haven't read the paper, of course).

Throwing Los Angeles County, CA and Brewster County, TX into the same bucket, coming up with an average county that represents neither, then picking a couple of arbitrary distances (100 and 200 miles) and assessing friend density within each, and, finally, extracting meaning from those two obviously meaningless numbers (which you readily grasp if you've been to both L.A. and Alpine) is ... stupid. When is average going to be over? When academics stop being paid to write papers about the amazing properties of the average apple-orange.

Pretty much all research that uses a large number of data points could be subject to roughly the same criticism. Some people do make such a criticism, but it amounts to a counsel of despair, because it means you can't really study anything.

That's not really true. You can carefully look at the data and try and compare like to like and clearly point out to the reader why you are doing so and the metrics you are using.

Actually, you can specify your model first and then run a test to generate some data. If the data fits well you're discovered something (e.g. https://www.theatlantic.com/science/archive/2016/07/how-a-guy-from-a-montana-trailer-park-upturned-150-years-of-biology/491702/ ) Sadly, only risk takers will look into an urn full of hypotheses, each with a prior probability of being true of 0.001 or less, pull out a promisingly interesting one and risk his reputation, time and future income by testing it. And most academics are by nature not risk takers. So instead they find some data, put their creative abilities into piecing it all together into a coherent and marketable (helpful, clever, weird, PC, etc.) narrative and sell it to the gullible public.

"So instead they find some data, put their creative abilities into piecing it all together into a coherent and marketable narrative "

LOL, ok, I agree with that point.

Haven't read the paper, but I have a future Nobel Prize in Social Studies (don't they have that? Yes they do: it's the Nobel Prize in Economics, there's such a thing?) along the following: the more wealthy you are, the further away are your friends (think Buffett and Gates playing bridge).

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