Excess Demand Financial Market Model
  Recently we reported on an application of the Tsallis non-extensive statistics to the S&P500 stock index. There we argued that the statistics are applicable to a broad range of markets and exchanges where anamolous (super) diffusion and 'heavy' tails of the distribution are present, as they are in the S&P500. We have characterized the statistics of the underlying security as non-extensive, and now we seek to generalize to the non-extensive statistics the excess demand models of investors that drive the price formation in a market. 
Fredrick Michael, John Evans, M.D. Johnson