China's current-account surplus - the combination of its trade surplus and its net income from foreign investments - is the largest in the world. With a trade surplus of $190 billion and the income from its nearly $3 trillion portfolio of foreign assets, China's external surplus stands at $316 billion, or 6.1 percent of annual GDP.

Because the current-account surplus is denominated in foreign currencies, China must use these funds to invest abroad, primarily by purchasing government bonds issued by the United States and European countries. As a result, interest rates in those countries are lower than they would otherwise be.

However, that may all be about to change, as the policies that China will adopt as part of its new five-year plan will shrink its trade and current-account surpluses.