Having spent 10 years studying emerging markets, I know that you have patterns repeated over and over again. A bubble is like a fire which needs oxygen to continue... when you see there is no oxygen, things change.

I think investing in a good education has been key for me, although the investment was more in time than money.

I'm not a pessimist by nature. I'm not someone who sees things in a bleak way.

A currency serves three functions: providing a means of payment, a unit of account and a store of value. Gold may be a store of value for wealth, but it is not a means of payment. You cannot pay for your groceries with it. Nor is it a unit of account. Prices of goods and services, and of financial assets, are not denominated in gold terms.

What we need to understand is, one, that there are market failures; and two, that there are things like asset bubbles and irrational exuberance. There are periods of booms, bubbles, and manias. These things, if left to themselves, can lead to crashes, to busts, to panics.

Technology is spurring innovation, and the so-called "demographic dividend" has brought change.

If we didn't have greed, market economies wouldn't be as innovative as they are. But in my view, greed has to be contained by the fear of losses, so there has to be a system where, if you take too much risk, you go into bankruptcy. You don't systematically bail out people who take excessive risks.