Wealth dynamics in pure exchange (no production) economic models. Starting from an equal distribution of wealth among N traders, different exchange rules modify this initial distribution across the time span t=1:T. At each point of time two traders are randomly selected. If both have positive wealth, an exchange takes place. Trades never induce negative wealth (no creditors are allowed). If wealth becomes zeros it represents an absorbing state.
The exchange rules are described in Hayes, B. (2002) "Follow the money", American Scientist, vol. 90, n. 5, p. 400–405. See also: Ispolatov, S., Krapivsky, P. L. and Redner, S. (1998) "Wealth distributions in asset exchange models", The European Physical Journal B2, p. 267–276.