In the light of the UK's impending referendum on membership of the European Union, I've been reading a bit about the distribution of powers in a layered political system. Various regions of the UK have rejected elected assemblies, while London, Scotland and Wales seemed to fairly enthusiastically embraced theirs. A lot of the debate seems to relate to different groups arguing over whether different layers (for us it goes from parish councils, to district, county, sometimes a regional assembly, national parliament, EU then in some ways the UN) can make useful decisions for their area of influence or will just be "talking shops".
Is there an analysis anywhere of how existing multilayered systems share their powers and, more speculatively, what an efficient distribution from the most local to the most global might be?