Government efforts
Mr Greenspan's comments come as significant uncertainty remains in global markets, amid fears that key economies have already entered a recession.
Some share markets and currencies have been especially volatile, prompting intervention by governments to prop up banks and boost the financial sector.
Recent developments include:
Russia has moved to boost its currency in the wake of a sharp slide in oil prices and declines in foreign investments. In the past week gold and foreign reserves are down $15bn (￡9.3bn) French President Nicolas Sarkozy on Thursday mooted setting up a state-run investment fund to help protect national firms and aid small firms in difficulty Sweden's central bank tried to boost its economy by cutting interest rates by half a percentage point to 3.75% and said it planned to make further cuts within six months Hungary unexpectedly increased its interest rate by three percentage points to 11.5% on Wednesday in a bid to boost its currency, the forint Earlier, some Asian indexes saw sharp falls, as investors worried about the prospect of a global recession.
South Korea's Kospi index was down 7.4%, its lowest close since July 2005, while Hong Kong's Hang Seng index was down 4.7%, at its lowest level since April 2005.
However, after a volatile session, the London FTSE 100 index ended up 1.16%, while France's Cac 40 rose 0.38% and Germany's Dax fell 1.13%.
