The fears of economists and politicians with regard to flexible exchange rates can largely be traced back to the policies of the 1920s following the collapse of the gold standard. The most famous criticism of flexible exchange rates is probably that made by the Estonian economist Ragnar Nurkse. Nurkse claimed that the 1920s demonstrated that flexible exchange rates are destabilising.
Friedman, however, is fiercely critical of Nurkse’s view. First of all Friedman claims that currency speculation is stabilising and, second, that much of the historical volatility that can be observed in flexible exchange rates is in fact due to poor economic policy – primarily poor monetary policy – and not a result of “currency speculators”.
As mentioned Milton Friedman claims that currency speculation is stabilising not destabilising. The purpose of currency speculation is basically to buy cheap and sell expensive. If a currency deviates from its fundamental value – ie, is overvalued or undervalued – it would be rational for the “currency speculator” to expect that the currency would sooner or later move towards its fundamental exchange rate. If the currency is, for example, undervalued – ie, is cheap relative to the fundamental exchange rate – it would be rational to expect that the currency will eventually strengthen, and thus the rational speculator will buy the currency. If the majority of speculators act in this way, the exchange rate will all else equal be driven in the direction of the currency’s fundamental value – thus currency speculation is stabilising. Friedman argues furthermore that speculators who do not speculate rationally – ie, who sell when the currency is undervalued and buy when it is overvalued – will not earn money in the long run. Such speculators will soon be looking for a new job, and thus there will be a tendency for the number of “stabilising speculators” to be relatively greater than the number of “destabilising speculators”.
According to Friedman floating exchange rates will remain relatively stable if the FX market is left to its own devices. However, the problem is that governments and central banks have had problems keeping their hands off. Even in the 1920s and after the collapse of Bretton Woods in 1971 when flexible exchange rates were the norm, governments and central banks intervened in global FX markets. Friedman claims this has actually increased volatility in FX markets rather than stabilised exchange rates. As both the 1920s and the 1970s were marked by inappropriate monetary policies, this further contributed to unstable exchange rates. Put another way, floating exchange rates require sensible monetary policy. This implies that to ensure low and stable inflation one must let the supply of money grow at a low and stable rate.
Flexible exchange rates provide no guarantee of sensible monetary policy, but they are a precondition for an independent monetary policy. If a small country pursues a fixed exchange rate policy it will automatically be forced to follow the monetary policy of the nation(s) that dominate the currency system. This will be a particular problem if the “small” country’s economy is hit by what in the modern theoretical literature is called an asymmetric shock.
An asymmetric shock is an economic event (for example a strike or a shift in fiscal policy) that only affects one of the countries in a fixed exchange rate mechanism and not the others. One example of this is the reunification of Germany. Both fiscal and monetary policy were eased considerably in Germany at the time of reunification. This stoked inflationary pressure in Germany to a level that caused the German central bank, the Bundesbank, to tighten monetary policy again in 1992. Most EU currencies were at the time linked to the German mark under the European Monetary System (EMS). In the early 1990s, the other EU countries were struggling to break out of a period of low growth and the majority of the European economies had absolutely no need for the monetary tightening they were indirectly subject to via their fixed exchange rate policy with Germany. In 1992 Milton Friedman predicted the consequences for the EMS:
“I suspect that EMS, too, will break down if Germany ever becomes unwilling to follow those policies, as it well may as a result of the unification of East and West Germany.”
The EMS broke down (partially) in 1993, proving Milton Friedman – as had been the case with the Canadian fixed exchange rate policy 43 years earlier – correct.
See also my posts in this series:
 Nurkse, Ragnar, “International Currency Experience: Lessons of Interwar Experience”, Genéve, 1944.
“Money Mischief”, page 245.