US dollars since 2000 on the substantial depreciation of major The substantial depreciation of the dollar increase in the global financial uncertainty， easy-to-induced financial And the continuous depreciation of the dollar in the process， the rest of the world's major economies， monetary policy is also in First of all， this article analyzes the reasons for the depreciation of the dollar， and then to explore the world's major economies in the context of monetary policy choices and difficult [Key words] dollar， the euro exchange rate， monetary policy First， the US dollar and the reasons for Since 1999， the US dollar against the euro exchange rate fluctuations Generally speaking， before 2001， the US dollar against the euro exchange rate was rising， but in 2002 after the dollar has Over the same period， the US dollar against other major economies has been a drastic devaluation of the currency， the US dollar on the 2001-2007 Japanese yen， pound sterling， the devaluation of the ruble rate was 4%， 28% and 19%; in July 2005 since China's exchange rate reform to In March 2008， the depreciation of the dollar against the yuan as much as 14% The substantial depreciation of the dollar due to what? To study the great dollar exchange rate fluctuations of the reasons， it is necessary to briefly review the basic theory of exchange rate (A) the basic theory of exchange rate decision PPP's basic view is that domestic and foreign currency exchange rate between the two countries depends on the purchasing power of the currency To do the same theory， in a certain period of time， changes in currency exchange rates with the same period of time between the two countries price level changes in the relative In other words， countries with higher inflation rate would be devalued its Through the years 1999-2007 and the US dollar against the euro， British pound， Japanese yen and changes in the price index difference between the use of software Eviews return and found that the correlation coefficient is less than 15， so that exchange rate movements and price changes are not related to purchasing power parity against the US dollar against the euro And other major currencies， exchange rate movements explain the lack of Interest rate parity theory， the forward rate of spread by the interest rate difference between the two countries decided that the high interest rate currencies in the foreign exchange market must discount period， the period of low interest rates in the country foreign exchange market must be But through the years 1999-2007 for the US dollar against the euro， British pound， Japanese yen exchange rate and interest rate differences between the two countries， the use of software Eviews return and found that the correlation coefficient is less than 3， so that the US dollar against the euro and other currency exchange rates and interest rate differences irrelevant， Interest rate parity does not hold Assets said to be on the market since the 1970s Western scholars focus on capital flows in the analysis of exchange rates in the role of the theory of multiple collectively， including multi-En Buci (R Dornbusch) overshoot of the model， Brown's (W Branson) of the Portfolio Selection Theory， and so However， due to the euro zone's largest economies， Germany on January 1 has always been heavy management of the traditional inflation in the euro zone price changes in the level of short-term changes in the exchange rate does not reflect the long-term changes in the track， the multi-En Buci overshoot the model can not explain the US Against the euro exchange rate fluctuations great; and Brown's main theoretical model applicable to small countries， the United States appears to be a major economic power that can not be Traditional theory can not explain the sharp fluctuations in the dollar， some scholars put forward the economic base determines the exchange rate of the theory in an attempt to verify the GDP growth rate and exchange rate fluctuations related ECB Executive Jurgen Stark (2008) pointed out that the mid-1990s， US labor productivity growth has been ahead of the euro zone， and the United States and Europe have differences in labor productivity， the expansion of the trend until 2006， before and after the euro zone to increase labor productivity Catch up with the United S Labor productivity is the main driver of growth， from Table 1 can clearly see that the euro zone in 1999-2007 of 9 years， overall economic growth than the United States， of which only 2001 and 2007 annual growth rate higher than that of the United States， basically the same as in 2006 And the remaining 6 were significantly lower than in the United S The US dollar against the euro in addition to the exchange rate basically stable in 2001， 2006 and 2007 showed strong rapid decline in 2002-2004， however， the euro zone's economic performance is weak， the dollar also fell，
