How does one define entitlement to enjoy the commons?

Blogging has died a little with the advent of facebook and twitter.  I am also very focussed on writing about the commons.

I have written a first draft of my book on the environmental history of the commons and currently waiting feedback from the publishers (MIT) and am know very deeply into a new book on Elinor Ostrom's work.

My Green Party collegue and friend Andrea Claire-Smith http://www.greenparty.org.uk/individual/291 wrote this in response to the first chapter of my book on the environmental history of the commons, which I think puts forward some interesting questions.

The issue that I kept returning to was how does one define entitlement to enjoy the commons? If one believes that the only boundary with legitimacy is the eggshell thin layer of atmosphere that surrounds this planet, then I would have the right  to move to the rainforest and inhabit the same territory as the people currently living there. If I was ripping up that forest, then it seems reasonable for them to object, but what if I promised to follow their established ways for living in that area? It seems that agreement to follow the lifestyle of people already successfully living in balance with the land would be a good criterion for receiving usufruct rights.
Then I thought of the public services that we have in the UK as a commons. How should it work if someone from outside of the UK wants usufruct rights for that commons? Should there be a criterion that they have to meet to enjoy these public services? Of course, there are numerous criteria but should they exist at all? If they should, what should they be?
I would not like to make a distinction between someone joining this society from another country to someone joining it because they were born here. If there is a criterion for the former, than it should be applied in the latter case too. But the problem with criteria is making sure they are fair and able to adapt to the diverse circumstances in which people find themselves.

Then there is entitlement on a group scale with the cases of either geographically overlapping groups using the same commons or as in the example you give from Thompson of different communities of interest using the commons for conflicting purposes. Both the entitlement of the individual and that of the group are touched on in many of the examples that you give and I wondered if you had plans to discuss in a later chapter how these can be arbitrated?
I had two further examples of commons. The commons system in New Forest which appears to integrate different uses of the forest successfully (maybe it doesn’t and that’s why you haven’t mentioned it! ) and the electricity system.

I was thinking of the electric grid as a commons. In this case the suppliers of electricity to the grid in the UK have not worked together to provide the public good of reliability of electricity supply because investing in generating capacity that is only occasionally used will benefit competitor’s customers as well as your own. It is a market failure and power shortfalls are not too far away. DECC proposed a strategic reserve – a small fleet of powers stations – that would only be brought into use when power cuts threatened. However, they have were persuaded to go for another type of market – a capacity market. The details of which are as yet undecided. This is not a failure of the commons though – just evolution of its management. The CEGB managed the grid pretty successful. I think electricity grid are example of successful commons where co-operation over the use of a resource – the ability to generate electricity -  is more efficient than individuals or groups operating without the benefits of connection.