I've always believed that a speculative bubble need not lead to a recession, as long as interest rates are cut quickly enough to stimulate alternative investments. But I had to face the fact that speculative bubbles usually are followed by recessions. My excuse has been that this was because the policy makers moved too slowly - that central banks were typically too slow to cut interest rates in the face of a burst bubble, giving the downturn time to build up a lot of momentum.
Paul Krugman