“They find that men serving in companies with tight social connections—like shared birthplace and occupation—were more likely to stand and fight than those in less tight-knit companies, where desertion rates were up to four times higher. The bonds of friendship also mattered for Union soldiers who ended up in Confederate POW camps: Soldiers imprisoned with others of similar backgrounds were much more likely to survive to see the war’s end.
When economists look at friendship and social networks, what they see is people trading favors—you scratch my back and I’ll scratch yours. A friendship’s value is determined by the benefits of favors you receive weighed against the cost of the favors you’ll need to do in return. A friendship built on cold economic foundations can be sustained only as long as the gains of the long-term trading of favors exceed the benefit of taking one last back scratch before putting an end to the relationship (though news travels fast, so retaliation from others in your social circle may help to keep you from taking advantage of others).”
Thought this was interesting. It sheds light more for Economists to study social relations and networks.
The rest is here.