Because of the extreme volatility of the currency market, the euro goes up and down significantly from month to month with respect to other currencies, it becomes very difficult to invest in it. There are significant advantages of strong currency.

In the current situation, no country wants to be the last to have a strong currency. Some economists, according to The Wall Street Journal, are concerned that countries try to weaken their currencies to gain an advantage over its trading partners, sparking a round of devaluations that ultimately, harm world trade.

In fact, the sharp decline of the dollar and the pound sterling has

sparked much concern in exporting countries such as Germany and Japan. In the month of December, the exportable products of these economies had a relative price rise of around 15% in countries like the USA and England, and in all nations that have tied their currencies to the dollar or the pound.

A strong currency, in any case, has its advantages. The dollar's drop has brought some relief to emerging markets whose currencies have taken a beating in recent months. That eases the burden on enterprises with foreign currency debt, which is very common in these countries.

In the late '90s, some emerging economies like Russia and Brazil were forced to devalue. Over time, the more competitive exchange rate helped them recover to unleash a wave of exports and exploit global demand was increasing. Today, however, activity has slowed worldwide, making it difficult for a country through exports rebound.

For the U.S., however, a weaker currency could provide desperately needed aid: stop a cycle of declining prices, commonly known as deflation. According to some economists, there is a pretty convincing economic argument that says if your problem is deflation, then lower the exchange rate is an effective method of attack.

How will this? There is one thing we can be sure, in the words of Simon Johnson, former IMF chief economist: "The world can not depreciate its currency against Mars and export to the rest of the solar system. Everything else, anything can happen.