> Simon didn't see the growing population as a catastrophic problem. He explained that we are not like any other species. We have an economy and markets. So, according to Simon, if the world demands more oil, the price of oil will go up, and there will be an incentive to find more, or find an alternative.

> Simon proposed that they bet on what would happen to the price of five metals — copper, chromium, nickel, tin and tungsten — over a decade.

> And the logic was that these metals were essential for all kinds of stuff — electronics, cars, buildings. So, if Ehrlich was right, more people on the planet would mean we would start running out of stuff, and the price of these things should go up.

> Those next 10 years, from 1980 to 1990, crept by. The world population grew by 800 million people. Then it was 1990. And they tallied it up. Simon, the economist, decisively won. Prices for the five metals went down by an average of 50 percent.

> One of the reasons the prices dropped was just what Simon said. The catastrophe Ehrlich was predicting just did not happen. People invented substitutes, like companies switching from aluminum to plastic for packaging.

Markets are more complicated and people are often irrational, but that doesn't mean the feedback loop isn't there. It is fallacious to assume that substitutes will be found and that technology will continually advance directionally. Conceptually, prices could simply rise to the point where only the very rich get to use personal computers until, 200 years later, genetic engineering brings organic AI.

In reality it's some mix of all the above and much more precisely because the world is irreducibly complex. But I think the point of creating and relying upon transparent markets is precisely so that pricing signals can reach people quickly; and if this induces the wrong behavior according to our normative objectives then it's easier to identify this and we can react accordingly without having to rely on conjecture and our imaginations.