Scientists as Policy Advisors
Many non-economist science bloggers have hailed Obama's appointments of scientists to key positions within his administration. But some people, including economists, have been a bit more hesitant about at least one appointment. Likewise I am not so sanguine about the appointments. Yes, it signals that Obama wants the best scientific information to guide his policies. But, is it enough? How many of those scientists are actually good policy wonks? Do any of them acknowledge how important the science of economics is to their policy proposals? There are unfortunately too many otherwise good scientists who have no knowledge of economics but are otherwise more than happy to make pronouncements on economics.
I hate to pick on Ethan Siegel over at Starts With A Bang! since he does really good work there. But, he also just happened to give me a perfect example. In "Can the Moon Help Solve Earth's Problems?" he asks:
How many humans can the planet support before we need to either reduce the population or expand to other worlds?
Ethan seems to claim we are near or approaching the limit:
We’ve already talked about how forests and wild places are needed to remove Carbon Dioxide from the atmosphere and reverse global warming, but let’s put that aside. We’ve got lots of arable land on this planet, and as the population goes up, more and more of that land is needed for farming, to feed the world. In order to do that, we need fewer forests: ...And we need to take that land and turn it into farmland for production of staple foods: ...The Earth currently produces staple foods (rice, grains, cereals, potatoes, etc.) in quantities of 2,264 million metric tonnes per year, enough to feed about 10 billion people assuming everyone eats a 2,000 calorie-per-day diet. ... So assuming we want to do the following:
* Keep our forests,
* Continue reproducing, and
* Continue feeding ourselves (and eating the good food, too),
what are our options? We clearly need more land, and we clearly can’t take any more from Earth, as we need more wild places and forests to help repair the damage that’s already been done. Where should we look?
Mu. The big problem an economist sees is the use of current food supply as different than food demand. But price theory is very clear: Supply equals demand in a clearing market. Food is a clearing market, even adding in various nuances such as political distortions of the market, transaction costs, and so forth. This factoid is worthless for calculating carrying capacity. There are a number of things that should be considered in calculating carrying capacity of the Earth.
First, is the land being cultivated being completely used? No. A significant amount of cultivated land is laying fallow each year in the U.S. I have heard estimates that the U.S. alone could feed the entire world with just the land currently cultivated. In the rest of the world, the yield per acre is nowhere near as high as in the U.S. and Canada - not because the soil or climate is better in North America, but just because it is not necessarily economic for farmers in other places to use the latest, greatest farming methods and tools. As developing nations further develop, the yield per acre of farmland will greatly increase.
Second, there is no evidence that yield per acre is anywhere near a maximum, even in the U.S. and Canada. The amount of cultivated land in the U.S. has actually been shrinking for a long time, yet total yields are still increasing.
Third, what about the land that is currently not arable but could be made so? What about using the oceans and seas for growing food?
Last but not least: what new developments - inventions, improved methods, whatever - will come along in the future that makes the whole thing moot? I won't even make a guess at the possibilities. The only thing I know is that as long as we have relatively free markets we'll get unpredictable new technologies.
My best estimate is that humanity will have to worry about the Sun's upcoming mid-life crisis long before we have to worry about population problems. Fortunately we have a few hundred million years before that becomes a problem.
Anyway, that was just to point out that a perfectly fine scientist should not be in a policy leadership role. On the other hand, I'd like to think that a rocket scientist with an interest in economics and political science would be perfectly fine for the job. So a scientist in a top policy role can be perfectly fine, but there is no guarantee. We need to look at each of them individually before we get excited.
I do not know enough about most of the appointees to really form an opinion on each of them individually. One that does stand out is John Holdren. In 1980 Holdren sided with and assisted Paul Ehrlich in establishing the terms of a bet with Julian Simon. The bet was whether certain commodity prices would go up or down over a decade. Simon handily won the bet, but as best as I can tell, Holdren did not and still does not accept that the reason Ehrlich lost was that Simon and most economists were and are right about the basic concept that on average each person creates more goods than that person consumes. Or to say it in a slightly different way - Holdren does not accept that on average, each additional person in the world makes all of us better off. And that is very dangerous.
We now have in our hands—really, in our libraries—the technology to feed, clothe, and supply energy to an ever-growing population for the next seven billion years.
(Simon "The State of Humanity: Steadily Improving" 1995)