There is a bit of a problem with the match between derivative securities markets and the primary markets. We have long ago instituted principles, essentially high margin requirements, to prevent certain instabilities in the stock market, and I think they're basically correct. The trouble is that there's a linkage, let's say, between something like the stock market and the index futures markets, and the fact that the margin requirements are very different, for example, played some role in the October '87 crash.

The world is changing. We're not really proceeding on a stationary basis.

In my [Impossibility] theorem I'm assuming that the information is a ranking. Each voter can say of any two candidates, I prefer this one to this one. So then we have essentially a ranking. It's a list saying this is my first choice. This is my second choice. Each voter, in principle, could be asked to give that entire piece of information. In the ordinary Plurality Voting, say as used in electing Congressmen, we generally only ask for the first choice. But, in principle, we could ask for more choices.

The Germans, for example, have some kind of compromise between single-member and broader districts. In Israel, you have nothing, you have only a national election. You have no local districts at all. And that's because of the idea that in addition to other ideological differences, locality matters. The question is does the congressman represent his district and the interests of his district? And as I said there's quite a variety of systems the democratic world. The implications need to be examined.

Markets are not, in my opinion, a full solution to any problem. The obvious problem they don't meet is the concerns of the welfare of individuals who may get lost in the operation of the system - the distributional question. We've seen this growing as we go further and further toward a market ideology in the United States and the United Kingdom. We've seen a decline in the welfare of the working poor, leaving aside any other pathologies, just the working poor, a very distinct increase at the very top levels.

One way of looking at Impossibility Theorem is that we proposed some criteria for what a good system should be: what is it you want from a voting system, and impose some conditions. And then ask: can you have a voting system that guarantees that?

I think on the efficiency level, not only the distribution level, capitalism is a flawed system. It probably has the same virtues as Churchill attributed to democracy: It's the worst system except for any other. And I think that's right, but it cannot be thought that some unmitigated belief in free markets is a cure even from the efficiency point of view.