  A simple computer simulation model of a closed market on a fixed network with
free flow of goods and money is introduced. The model contains only two
variables : the amount of goods and money beside the size of the system. An
initially flat distribution of both variables is presupposed. We show that
under completely random rules, i.e. through the choice of interacting agent
pairs on the network and of the exchange rules that the market stabilizes in
time and shows diversification of money and goods. We also indicate that the
difference between poor and rich agents increases for small markets, as well as
for systems in which money is steadily deduced from the market through
taxation.
