Professor Alan Ahearne:

That I do not know. What I do know is this - as I mentioned in my statement, they are surprisingly common. Some countries have booms and busts every couple of decades. That has to tell us something about how popular they are and how difficult it is to stop them. If we only had one or two and did not have another one in 40 years, we would say: "We learnt the lessons and now it is easy to stop booms and busts." However, the fact that they repeat so often and there are so many of them, tells us that when they get going there must be something in the system that makes it very difficult, even though we know they are devastating if one gets hard landings. We know they do terrible things to society and to people's standard of living.