How a rough system of barter developed into a more complex system of trade in WWII POW camps. This is fascinating stuff.
We reached a transit camp in Italy about a fortnight after capture and received 1/4 of a Red Cross food parcel each a week later. At once exchanges, already established, multiplied in volume. Starting with simple direct barter, such as a non-smoker giving a smoker friend his cigarette issue in exchange for a chocolate ration, more complex exchanges soon became an accepted custom. Stories circulated of a padre who started off round the camp with a tin of cheese and five cigarettes and returned to his bed with a complete parcel in addition to his original cheese and cigarettes; the market was not yet perfect. Within a week or two, as the volume of trade grew, rough scales of exchange values came into existence. Sikhs, who had at first exchanged tinned beef for practically any other foodstuff, began to insist on jam and margarine. It was realized that a tin of jam was worth 1/2 lb. of margarine plus something else; that a cigarette issue was worth several chocolates issues, and a tin of diced carrots was worth practically nothing.
The cigarette soon became the coin of the realm and at camps with stable populations, there were shops operated by the senior British officer with cigarettes as the currency people used to buy and sell goods to/from the store.
One trader in food and cigarettes, operating in a period of dearth, enjoyed a high reputation. His capital, carefully saved, was originally about 50 cigarettes, with which he bought rations on issue days and held them until the price rose just before the next issue. He also picked up a little by arbitrage; several times a day he visited every Exchange or Mart notice board and took advantage of every discrepancy between prices of goods offered and wanted. His knowledge of prices, markets and names of those who had received cigarette parcels was phenomenal. By these means he kept himself smoking steadily - his profits - while his capital remained intact.
The article also discusses deflation, the shifting availability of currency, credit, price movements, futures markets, paper currency, and price fixing. (via migurski)