Murray N. Rothbard
Government Meddling With Money
With fiat money established and gold outlawed, the way is clear for full-scale, government-run inflation. Only one very broad check remains: the ultimate threat of hyper-inflation, the crack-up of the currency. Hyper-inflation occurs when the public realizes that the government is bent on inflation, and decides to evade the inflationary tax on its resources by spending money as fast as possible while it still retains some value. Until hyper-inflation sets in, however, government can now manage the currency and the inflation undisturbed. New difficulties arise, however. As always, government intervention to cure one problem raises a host of new, unexpected problems. In a world of fiat moneys, each country has its own money. The international division of labor, based on an international currency, has been broken, and countries tend to divide into their own autarchic units. Lack of monetary certainty disrupts trade further. The standard of living in each country thereby declines. Each country has freely-fluctuating exchange rates with all other currencies. A country inflating beyond the others no longer fears a loss of gold; but it faces other unpleasant consequences. The exchange rate of its currency falls in relation to foreign currencies. This is not only embarrassing but even disturbing to citizens who fear further depreciation. It also greatly raises the costs of imported goods, and this means a great deal to those countries with a high proportion of international trade.
In recent years, therefore, governments have moved to abolish freely-fluctuating exchange rates. Instead, they fixed arbitrary exchange rates with other currencies. Gresham's Law tells us precisely the result of any such arbitrary price control. Whatever rate is set will not be the free market one, since that can be only be determined from day-to-day on the market. Therefore, one currency will always be artificially overvalued and the other, undervalued. Generally, governments have deliberately overvalued their currencies?for prestige reasons, and also because of the consequences that follow. When a currency is overvalued by decree, people rush to exchange it for the undervalued currency at the bargain rates; this causes a surplus of overvalued, and a shortage of the undervalued, currency. The rate, in short, is prevented from moving to clear the exchange market. In the present world, foreign currencies have generally been overvalued relative to the dollar. The result has been the famous phenomenon of the "dollar shortage"?another testimony to the operation of Gresham's Law.
Foreign countries, clamoring about a "dollar shortage," thus brought it about by their own policies. It is possible that these governments actually welcomed this state of affairs, for (a) it gave them an excuse to clamor for American dollar aid to "relieve the dollar shortage in the free world," and (b) it gave them an excuse to ration imports from America. Undervaluing dollars causes imports from America to be artificially cheap and exports to America artifically expensive [Ed. Note: this sentence was truncated in the 4th edition]. The result: a trade deficit and worry over the dollar drain.  The foreign government then stepped in to tell its people sadly that it is unfortunately necessary for it to ration imports: to issue license to importers, and determine what is imported "according to need." To ration imports, many governments confiscate the foreign exchange holdings of their citizens, backing up an artificially high valuation on domestic currency by forcing these citizens to accept far less domestic money than they could have acquired on the free market. Thus, foreign exchange, as well as gold, has been nationalized, and exporters penalized. In countries where foreign trade is vitally important, this government "exchange control" imposes virtual socialization on the economy. An artificial exchange rate thus gives countries an excuse for demanding foreign aid and for imposing socialist controls over trade. 
At present, the world is enmeshed in a chaotic welter of exchange controls, currency blocs, restrictions on convertibility, and multiple systems of rates. In some countries a "black market" in foreign exchange is legally encouraged to find out the true rate, and multiple discriminatory rates are fixed for different types of transactions. Almost all nations are on a fiat standard, but they have not had the courage to admit this outright, and so they proclaim some such fiction as "restricted gold bullion standard." Actually, gold is used not as a true definition for currencies, but as a convenience by governments: (a) for fixing a currency's rate with respect to gold makes it easy to reckon any exchange in terms of any other currency; and (b) gold is still used by the different governments. Since exchange rates are fixed, some item must move to balance every country's payments, and gold is the ideal candidate. In short gold is no longer the world's money; it is now the governments' money, used in payments to one another.
Clearly, the inflationists' dream is some sort of world paper money, manipulated by a world government and Central Bank, inflating everywhere at a common rate. This dream still lies in the dim future, however; we are still far from world government, and a national currency problems have so far been too diverse and conflicting to permit meshing into a single unit. Yet, the world has moved steadily in this direction. The International Monetary Fund, for example, is basically an institution designed to bolster national exchange control in general, and foreign undervaluation of the dollar in particular. The Fund requires each member country to fix its exchange rate, and then to pool gold and dollars to lend to governments that find themselves short of hard currency.
In the last few years, the dollar has been overvalued in relation to other currencies, and hence the dollar drains from the U.S.
For an excellent discussion of foreign exchange and exchange controls, see George Winder, The Free Convertibility of Sterling (London: The Batchworth Press, 1955).