Economics is a branch of ecology
In an interview published in 1996, Garret Hardin stated:
The view that I and a number of other ecologists share is that ecology is the overall science of which economics is a minor specialty.
(HT to Rob Brooks for the quote - it is at the beginning of his book Sex, Genes & Rock ‘n’ Roll)
I agree with Hardin’s sentiment. As I have advocated in this blog before, economics would be much richer, have more predictive power and offer a better description of the world if economists used the fact that humans are a product of billions of years of evolution and this process shaped our traits and preferences. Economics will always be within that framework.
However, I have two disagreements with Hardin’s choice of wording. First, I would leave out the word “minor”. While humans are one of millions of species, humans are important - with this belief held by most humans. When we seek to explain these rather important creatures, such as examining our day-to-day life, economics provides some of the most important tools. Despite being a part of ecology, economics is important for us.
Also, on ecological grounds, humans are rather dominant. Paul MacCready estimated that humans and their livestock have moved from less than 1 per cent of the world’s vertebrate biomass before the dawn of agriculture to around 98 per cent now (I picked this factoid up from a speech by Daniel Dennett). When we address the ecological issues humans have created, economics plays a central role.
The second point of disagreement is the implicit description of ecology as the “overall science”. It is, of course, possible to take this deconstruction further. Is biology just glorified chemistry? Or physics?
Despite the potential for arguments that some branches of science are derivative of other, the division of the branches is useful. In economics, we don’t always need to ask what the evolutionary basis of a specific characteristic is. If we see it in experimental results, it might be useful to take it as given and to ask what this trait means economically. Similarly, if we see a certain behaviour in animals, we don’t always need to inquire into the brain chemistry. What level is appropriate will depend on the hypothesis being tested.
However, we do need to know when to call on these other sciences. In the same way that chemists should know some physics and biologists should know some chemistry, economists should know some biology to place the discipline its context and to know when it is useful to treat economics as a part of a larger science.