Central banks have traditionally sought to control inflation through their monetary policy tools, but that mandate may be starting to expand around the world, according to a recent Bloomberg analysis of the topic. Central banks are starting to dabble in other areas like economic growth, employment and/or financial stability when inflation threats are not immediate.
The U.S. Federal Reserve already has a dual mandate of controlling inflation and promoting employment and many other central banks have followed its lead. The Bank of England has focused on its economic growth rates, the ECB helped bailout troubled countries by purchasing bonds, and the Bank of Japan may soon take a far more active role after the elections.
For an in-depth analysis, see Bloomberg's article here:
http://www.bloomberg.com/news/2012-12-10/central-banks-ponder-going-beyond-inflation-mandates.html