<P> While a freely floating national money has advantages, however, it also has risks . For one thing, it can create uncertainties for international traders and investors . Over the past five years, the dollar has been worth as much as 120 yen and as little as 80 . The costs of this volatility are hard to measure (partly because sophisticated financial markets allow businesses to hedge much of that risk), but they must be significant . Furthermore, a system that leaves monetary managers free to do good also leaves them free to be irresponsible--and, in some countries, they have been quick to take the opportunity . </P> <P> Debate over the Nixon Shock has persisted to the present day, with economists and politicians across the political spectrum trying to make sense of the Nixon Shock and its impact on monetary policy in the light of the financial crisis of 2007--2008 . </P>

When was the last time the us dollar was backed by gold