But how do these rules emerge and why?
Empirical study of a lot of cases of the tragedy of the commons and an analysis where people found a way to successfully deal with the issue versus cases where they didn't.
The fact that she actually did study analysed >100 different real world episodes of tragedy was the work that earned her the "nobel prize".
This is prompted by Scott's excellent article, Meditations on Moloch.
I might caricature (grossly unfairly) his post like this: