If you are sick of posts about soccer and economics on this site, read no further. But Ted Miguel at UC Berkeley has sent me an interesting paper of his (co-authored with Sebastián M. Saiegh and Shanker Satyanath) which documents an intriguing empirical fact. Players in European leagues who come from countries with histories of civil war are more likely to behave violently on the soccer field, as measured by the number of yellow cards (cautions) they receive. Here is the picture that goes with the finding:
(The two countries in the top right corner are Israel and Colombia.) Miguel and his co-authors show that this relationship is robust to a number of controls, including income level of home country, continent of origin, position played (defender versus mid-fielder), and age.
Miguel et al. interpret this finding as suggesting that culture plays a role in determining propensity to violence and aggression. Whether civil wars are the result of such a culture or foster it, individuals who come from such environments carry certain proclivities that take apparently some time to dissipate.
I must say the cultural explanation leaves me cold, even though I do not have a good alternative explanation in its place. If you have ever spent time in cabs in Manhattan, you know that it is pretty hard to distinguish the Russian drivers from the Pakistani ones, or the Israeli ones from the Koreans. They all drive like NYC cabbies, even though the "driving culture" in these countries are pretty different.
UPDATE: Ted Miguel writes in response to some of the comments:
One of the big concerns folks had was robustness to outliers. It turned out our original figures were "raw" plots, but when we condition on the same variables as in the regressions - which is the "right" way to do
things - the plots look considerably stronger. If you're interested, I've just posted the latest version on my website.
Here is the "conditional" scatter plot, without Colombia and Israel.