gold output growth has approximately kept pace with world population growth (i.e. a doubling in this period) although it has lagged behind world economic growth (an approximately eightfold increase since the 1950s, and fourfold since 1980). Theory Commodity money is inconvenient to store and transport in large amounts. Furthermore, it does not allow a government to manipulate the flow of commerce with the same ease that a fiat currency does. As such, commodity money gave way to representative money and gold and other specie were retained as its backing. Gold was a preferred form of money due to its rarity, durability, divisibility, fungibility and ease of identification, often in conjunction with silver. Silver was typically the main circulating medium, with gold as the monetary reserve. Commodity money was anonymous, as identifying marks can be removed. Commodity money retains its value despite what may happen to the monetary authority. After the fall of South Vietnam, many refugees carried their wealth to the West in gold after the national currency became worthless. Under commodity standards currency itself has no intrinsic value, but is accepted by traders because it can be redeemed any time for the equivalent specie. A U.S. silver certificate, for example, could be redeemed for an actual piece of silver. Representative money and the gold standard protect citizens from hyperinflation and other abuses of monetary policy, as were seen in some countries during the Great Depression. Commodity money conversely led to deflation. Countries that left the gold standard earlier than other countries recovered from the Great Depression sooner. For example, Great Britain and the Scandinavian countries, which left the gold standard in 1931, recovered much earlier than France and Belgium, which remained on gold much longer. Countries such as China, which had a silver standard, almost entirely avoided the depression (due to the fact it was then barely integrated into the global economy). The connection between leaving the gold standard and the severity and duration of the depression was consistent for dozens of countries, including developing countries. This may explain why the experience and length of the depression differed between national economies. Variations A full or 100%-reserve gold standard exists when the monetary authority holds sufficient gold to convert all the circulating representative money into gold at the promised exchange rate. It is sometimes referred to as the gold specie standard to more easily distinguish it. Opponents of a full