Game theory can be used to explain behaviour in shared environments such as Grid or Cloud.

One could argue that a Cloud environment is much like non-cooperative game setting where one player is unaware of the other players.  An internal Grid, on the other hand, *may* still be non-cooperative but the other players are known.

Nash Equilibrium requires coordination between and amongst the parties in order to achieve an optimal solution.  The ratio of the solution achieved in NE vs. what really happens in the real-world is the Price of Anarchy.  The goal is reduce PoA for a shared environment.