How to Kill a Dollar

BERKELEY – The dollar has had its ups and downs, but the downs have clearly dominated of late. The greenback has lost more than a quarter of its value against other currencies, adjusted for inflation, over the last decade. It is down by nearly 5% since the beginning of 2011, matching the lowest level plumbed since the Bretton Woods System of pegged exchange rates collapsed in 1973.

An obvious explanation for this weakness is the United States Federal Reserve’s near-zero interest-rate policy, which encourages investors to shift from dollars to higher-yielding foreign assets. Predictably, the Fed’s critics are up in arms. The central bank, they complain, is debasing the dollar. It is eroding the currency’s purchasing power and, with it, Americans’ living standards.

Even worse, the Fed is playing with fire. Its failure to defend the dollar, the critics warn, could ignite a crisis of confidence. At some point, the Fed’s tolerance of a weak dollar would be taken as a lack of commitment to price stability. Frustrated investors would then dump their US Treasury securities. Bond yields would shoot up. The dollar would plummet. There would be financial distress and a deep recession.

Scary stories sell newspapers, but in truth all of this sniping at the Fed is overdone. Historically, a 10% fall in the dollar translates into only a one-percentage-point rise in inflation. This means that the dollar’s 5% fall so far this year will add only half a percentage point to the inflation rate.