Flexible Exchange RatesMost exchange rates are determined by the foreign exchange market, known as forex. For this reason, exchange rates vary on a moment-by-moment basis, depending on what traders think the currency is worth. This depends on a lot of factors, including central bank interest rates, the country's debt levels, and the strength of its economy. Most countries allow their currencies to be determined by the forex market. This is known as a flexible exchange rate.
The U.S. allows the forex market to determine its value. The dollar strengthened against most currencies during the 2008 financial crisis. As stock markets around the world fell, traders flocked to the relative safety of the dollar. Why was the dollar safe? After all, the crisis started in the U.S. and worsened until March 2009. Despite this, most investors trusted that the U.S. would guarantee the safety of the world's global currency. The dollar effectively replaced the gold standard, thanks to the Bretton Woods agreement. For example, the dollar was worth $1.39 Canadian dollars. For more on the dollar's role, see Value of the U.S. Dollar and Power of the U.S. Dollar.
Fixed Exchange RatesOne country that has a fixed exchange rate is China. It pegs its currency, the yuan, to a fixed value against the dollar. As of September 30, 2013, one dollar was worth 6.12 Chinese yuan. The dollar has weakened against the yuan since February 7, 2003, when a dollar could be exchanged for 8.28 yuan.
China has to manually adjust the exchange rate of the yuan to the dollar. That's because the U.S. government pressured the Chinese government to let the yuan rise in value. This allows U.S. exports to be more competitively priced in China. It also makes Chinese exports to the U.S. more expensive. For more on how this affects you, see U.S. China Trade Deficit.
Why the Euro Is SpecialMost exchange rates are given in terms of how much a dollar is worth in the foreign currency. The euro is different. It's typically given in terms of how much a euro is worth in dollars. It's hardly ever given the other way around. So, although the dollar was worth .75 euros on September 30, 2013,, you would only hear that one euro was worth $1.33.
The euro has weakened considerably since its all-time high of $1.60 on April 22, 2008. That's because the future of the European Union and the euro itself was in doubt during the Greek debt crisis. In addition, the European Central Bank (ECB) lowered its interest rate. This lowered bank rates for anyone lending or saving in euros, also reducing the value of the currency itself. At its worst, the euro's value plummeted to $1.22 on August 2, 2012. For more on the history of exchange rates between the dollar and the euro, see Euro to Dollar Conversion.(Source: Federal Reserve Bank of New York web site)
Nevertheless, the euro is special is because it is the second most popular currency after the dollar. It is used by 332 million people as their sole currency. The euro's popularity derives from the power of the European Union, which is the largest economy in the world. Even though the euro hasn't been adopted by all EU countries, no other currency comes close to being a global currency. Article updated September 30, 2013