US economy is properly regulated by the monetary policy of the federal government. This was intended at controlling the supply of money using various methods like changing interest rates. The final aim of this monetary policy was to maintain inflation at the lowest level and ensure high economic growth. This will keep the unemployment rate of the nation low. A stable currency and monetary policy was achieved with the help of the Federal Reserve which is the independent central bank formed in US. This is why US currency, dollar remains stable as compared to the currencies of other nations and is used by them.