Theory of enhanced performance emerging in a sparsely-connected   competitive population
  We provide an analytic theory to explain Anghel et al.'s recent numerical finding whereby a maximum in the global performance emerges for a sparsely-connected competitive population [Phys. Rev. Lett. 92, 058701 (2004)]. We show that the effect originates in the highly-correlated dynamics of strategy choice, and can be significantly enhanced using a simple modification to the model. 
T.S. Lo, K.P Chan, P.M. Hui, and N.F. Johnson