The nominated future chairman of the United States Federal Reserve has robustly defended the central bank's stimulus measures.
Janet Yellen is the woman the White House wants to run the Federal Reserve from next year, but she must first win the approval of the Senate.
She has been answering questions from senators on Capitol Hill as they consider whether to approve her nomination, and her responses drove Wall Street to an all time high.
Dr Yellen told senators that the central bank's quantitative easing programme, which aims to boost the economy by making cheap money available to banks, is worth the cost.
"I consider it imperative that we do what we can to promote a very strong recovery," she says.
She says the programme is being assessed as it continues and at this point she believes the benefits exceed the costs.
