The reserve ratio increases are one method China can use to keep its strong economy from overheating.
But China's tightening comes as the Federal Reserve plans for more quantitative easing. The Fed plans to inject money into the economy by buying $600 billion in long-term Treasuries over the next eight months.
The Fed's plan has been attacked by many politicians and economists as a program that effectively undermines the value of the dollar. At the same time, U.S. officials have also been critical of China for keeping its own currency, the yuan, artificially low.
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