In this paper, we study the inequality indices for some models of wealth
exchange. We calculated Gini index and newly introduced k-index and compare the
results with reported empirical data available for different countries. We have
found lower and upper bounds for the indices and discuss the efficiencies of
the models. Some exact analytical calculations are given for a few cases. We
also exactly compute the quantities for Gamma and double Gamma distributions.Comment: 10 pages, 7 figures; accepted in Physica