We study a statistical model consisting of N basic units which interact
with each other by exchanging a physical entity, according to a given
microscopic random law, depending on a parameter 位. We focus on the
equilibrium or stationary distribution of the entity exchanged and verify
through numerical fitting of the simulation data that the final form of the
equilibrium distribution is that of a standard Gamma distribution. The model
can be interpreted as a simple closed economy in which economic agents trade
money and a saving criterion is fixed by the saving propensity 位.
Alternatively, from the nature of the equilibrium distribution, we show that
the model can also be interpreted as a perfect gas at an effective temperature
T(位), where particles exchange energy in a space with an effective
dimension D(位).Comment: 5 pages, including 4 figures. Uses REVTeX styl