“…A major limitation of these money-only exchange models considered earlier [3,38,37,39,40,25,50,51,52,80,81,82,83,47,48,49,43,4 is that they do not make any explicit reference to the commodities exchanged with the money and to the constraints they impose on the exchange process. Also, the wealth is not just the money is possession (unless the commodity exchanged with the money is strictly consumable).…”