What does Sen have to do with Malthus?

A commenter questioned my association of Sen with Malthus the other day in my thinking-out-loud lecture planning, and I thought I'd elaborate a little more.

First, when I present the class with "modern Smithians" or "modern Malthusians" I like cases that don't precisely match up. Why? Because economic science is progressive and for the most part ideas persist but are changed, formalized, evolved, etc. I'm sure I could find people that think Smith or Malthus or Keynes had it EXACTLY right and that we should treat their work like scripture, but those sorts of people aren't very good representatives of economic science (and - tellingly - it's hard to find those sorts of people in the highest ranks of the science). If, instead, you have someone that takes a Smithian or Malthusian idea and then develops it, that gives the class something to talk about and think about in terms of the development of economic thought (which is, after all, what the course is about). I am very explicit about this in class discussions - that these thinkers are not exactly the same.

But there obviously has to be some continuity - so why associate Sen with Malthus? First, both were concerned with what Malthus would call "positive checks" and their impact on the poor, with population, with inequality, and with famine. So just like the endogenous fertility modelers I talked about (Oded Galor), we have a common research agenda.

But I'm not sure a common research agenda alone would be sufficient. The students actually read Malthus, they don't get the sound-bite version of Malthus, and by reading him they learn that he actually did not think that the poor were doomed to die of famine because there just wasn't enough food. Famine is one of the positive checks, but it is treated quite distinctly from the other positive checks. Malthus thinks famine is an unusual case. He notes that unlike positive checks like war or disease, people go through famine as a result of their relative ability to participate in markets. A rich person may very well die of disease (perhaps at a lower rate than the poor), but only the poor will starve to death. Famine can be ameliorated by market exchange in a way that a lot of the other positive checks can't, and therefore it is uniquely governed by the state of income distribution.

This is what we see in Sen, of course. Famines are not cases where not enough food is produced. Instead, famines are cases where not enough food can be purchased - they are a problem of distribution, not production. As a result they principally impact the lower classes.

We also talked about an interesting discussion in Malthus on why this is not widely discussed. Malthus's answer foreshadows two other modern research agendas. First, he says that nobody writes histories of the poor. People only write histories of war, politics, and the wealthy. His principle of population was likely operating for all of human history but people missed it because nobody had any interest in writing histories of the lower classes. This observation foreshadows the "social history" movement of the 1960s (which continues with force today), and of course earlier efforts at that sort of social history by Engels, etc. Malthus also argues that people have ignored the population pressures he discusses because of the difficulty of thinking in terms of real wages (remember - this is the age before price indices were easily downloadable!). He explains why nominal wages are generally downwardly rigid, and since adjustments for real wages are difficult people miss the decline in real wages. This, of course, foreshadows the burgeoning literature on real wage cyclicality in the late twentieth century.

I like this use of "modern Smithians" and "modern Malthusians" in the class. Most of the students are unfamiliar with the people I discuss, so it introduces them to important twentieth century economists. It also gives me an opportunity to make important observations on how science develops over time.

We are getting into Ricardo tomorrow (if Kate doesn't go into labor, that is). I'm probably not going to talk about any modern Ricardians on the first day (when we discuss factor prices), although I'll obviously note the proto-marginalism, or the second day on trade (except to note that this view is dominant aside from the "new trade theory", which we already discussed in the Smith class). But on the third day when we talk about Ricardo on public finance and on machinery I'm going to bring up Robert Barro as a modern Ricardian (for the public finance discussion we're going to be reading portions from his Essay on the Funding System that go over what we now call "Ricardian equivalence").

I'd be interested in hearing thoughts on any other "modern Ricardians" worth discussing in any of these classes as well.