The impact of US stimulus moves at home and abroad
18 September 2013 Last updated at 00:03 BST
Like many other central banks, the US Federal Reserve took steps to try and revive its economy after the global financial crisis struck in 2008.
Billions of dollars have been pumped into the economy through quantitative easing, but there are now plans to gradually reduce this before ending the stimulus measure in 2014.
The BBC's Stephanie Flanders examines the impact of the Federal Reserve's actions, both on its own economy and on a wider scale.