http://www.ted.com/talks/richard_wilkinson.html
Comparing inequality between nations per GDP vs internal inequalities in wealth in a nation and how it affects socities.
Again the lessons are obvious and do speak to a post peak world, reducing glaring inequality (not necessarily levelling societies just not having such naked robber barron attitudes).
We can live in a world with less energy, with less GDP and less material wealth yet live better, more fulfilled lives. Probibly live healthier as well.