Though this theory had been originally derived from the entropy maximization principle of statistical mechanics, it had been shown by A. S. Chakrabarti and B. K. Chakrabarti that the same could be derived from the utility maximization principle as well, following a standard exchange-model with Cobb-Douglas utility function. Recently it has been shown that an extension of the Cobb-Douglas utility function (in the above-mentioned Chakrabarti-Chakrabarti formulation) by adding a production savings factor leads to the desired feature of growth of the economy in conformity with some earlier phenomenologically established growth laws in the economics literature. The exact distributions produced by this class of kinetic models are known only in certain limits and extensive investigations have been made on the mathematical structures of this class of models. The general forms have not been derived so far. For a recent review (in 1924) on these developments, by M. Greenberg (Dept. Economics, University of Massachusetts Amherst & Systems Engineering, Cornell University) and H. Oliver Gao (Systems Engineering, Cornell University) in the last twenty five years of research on kinetic exchange modelings of income or wealth dynamics and the resulting statistical properties, see.