The exchange rate and the trade balance

Exchange rate flexibility is commonly justified as an efficient method for adjusting the trade balance to some desirable net international capital flow. In this orthodox view, fluctuations in a country's terms of trade or its saving-investment balance would continually upset its balance of payments equilibrium if the nominal exchange rate remained rigid.But this prevailing doctrine favoring exchange flexibility is only correct when economies are insular, ie. have limited trade and financial arbitrage with the outside world. With the spread of exchange controls and trade restrictions in the 1930s into the 1950s, the industrial countries became somewhat insulated from each other. A devaluation could then have the conventional effect of reducing a trade deficit because monetary and exchange rate policy were separable.Among the open industrial economies of the 1980s, however, financial arbitrage is uninhibited and trade is fairly free. Monetary policy, both current and prospective, now dominates what happens to the exchange rate. Because a devaluation today reflects an easier money policy in the present, or an expected easing in the future, it no longer has any predictable impact on the monetary value of the net trade balance. Exchange rate flexibility loses its usefulness in controlling net exports while becoming highly disruptive to the economy's macroeconomic stability.For example, the American dollar's downard float over the past three years should not be (have been) expected to improve the U.S. current account. However, allowing the dollar to depreciate below its purchasing power parity greatly increases the inflationary potential in the Americian economy.