By Bryan Caplan
When I was finishing up my book on voter irrationality, I had a lot of trouble tracking down any quotes confirming my belief that economists roughly buy into Julian Simon’s views on the benefits of population. In the end, I decided I was probably over-estimating Simon’s influence, and toned down that part of the book.
It now looks like I gave up too soon. In a recent interview by the Richmond Fed, Robert Moffitt, Editor of the American Economic Review, confirms that my initial reading of the pulse of the economics profession was right:
RF: There are some who have argued that population growth will ultimately lead to severe social and economic problems. I’m thinking of people like Paul Ehrlich, for instance. And then there are others — Julian Simon probably being the most prominent example — who have argued that population growth has unambiguously positive effects. Let us assume that these two positions define the extreme positions of the debate. Which one do you find more consistent with the evidence?
Moffitt: Although I have done work on the economics of fertility, I have not done work on this specific question. However, I have followed the debate fairly closely. As far as I can tell, the best work on that issue can be found in a couple of volumes put out by the National Academy of Sciences that examined how population growth affects a whole host of issues, including the environment, health, per-capita income, and others. And when you look at the data, it’s fairly hard to find major negative consequences of population growth. You can build models where this might be the case, but the empirical evidence seems fairly straightforward, and it is closer to Julian Simon’s view than to Paul Ehrlich’s.
I think that economists have generally been persuaded that population growth, on average, has positive effects — and so, too, have demographers, a group that used to include a pretty large number of population growth opponents. Also, I think most people would agree that we do not face a “population bomb” except, possibly, in Africa, and AIDS has changed things rather dramatically there. Quite the opposite: In many developed countries, population growth is now below the replacement rate.