When large companies take on risk, then they impose risks on the rest of the system. And these are systemic risks and these systemic risks we never used to think were really that important, but as soon as we recognize how the financial sector - the risks the financial sector takes on can impact the entire global economy, we realize that those risks needed to be controlled for the social good.

The collateralized debt obligation, the CDO, is a structure which allows you to more or less continuously choose how much risk you want to take in a whole batch of securities. And the reason why they got us into so much trouble is that it's hard to figure out how much risk you really are taking.

We're talking about should we increase taxes? Why not put a tax on carbon emissions. It would raise a lot of money, it would reduce the environmental damages in the future, it would solve so many problems, and it would be a much more constructive thing to do than to think about raising the income tax.

There are a lot of ways that investment banking models work, but these risks are not internalized by the people that are taking them.

Allowing short selling is allowing people to sell - instead of having to buy the stock and then sell it, which doesn't do much; allow them to sell it, and then buy it. In which case they can express that information and the idea is that you would get more accurate valuation of companies by letting people express both their positive information and their negative information through either long or short selling.

I think we're fooling ourselves if we think that regulators are going to be able to outsmart the bankers. So, the task of designing regulatory reform is trying to make more or less foolproof regulation and that's one of the advantages of the systemic category.

I think the credit default swaps can take the place of the rating agencies who really have missed the ball in this procedure and are quite conflicted by the way the ratings are paid for. So, I would like to see credit default swaps become an evermore important way of understanding credit risk in the economy.