Unsolved problems, that's one of the great signs of progress in my opinion.

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?

There's only one problem that bothers me. And that's something my theorem [ of Impossibility] really doesn't cover. In my theorem I was assuming people vote sincerely. The trouble with methods where you have three or four classes, I think if people vote sincerely they may well be very satisfactory. The problem is the incentive to misrepresent your vote may be high.

Evolutionary theory tends to explain quite well in retrospect how various species emerged. It's not very good on prediction. Nevertheless, one cannot say that there isn't a lot of knowledge that's been obtained in this field. In the same way, with these complex physical phenomena between solid state physics, you can say a lot of things without necessarily knowing the next step.

Venture capital has done much more, I think, to improve efficiency than anything.

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 thing I learned from meteorology is that being an actual science was no guarantee of exactness.