Is Economics a Science?

Eric Maskin, 2007 Nobel Prize winner in Economics, responds to Alex Rosenberg and Tyler Curtain’s characterization of economics:

They claim that a scientific discipline is to be judged primarily on its predictions, and on that basis, they suggest, economics doesn’t qualify as a science.

Prediction is certainly a valuable goal in science, but not the only one. Explanation is also important, and there are plenty of sciences that do a lot of explaining and not much predicting. Seismology, for example, has taught us why earthquakes occur, but doesn’t tell Californians when they’ll be hit by “the big one.”

And through meteorology we know essentially how hurricanes form, even though we can’t say where the next storm will arise.

In the same way, economic theory provides a good understanding of how financial derivatives are priced….But that doesn’t mean that we know whether the derivatives market will crash this year.

Perhaps one day earthquakes, hurricanes and financial crashes will all be predictable. But we don’t have to wait until then for seismology, meteorology and economics to become sciences; they already are.

Maskin’s examples should really indicate that seismology and meteorology do make predictions; they just happen to be probabilistic ones like ‘there will almost certainly be an earthquake measuring 7 on the Richter scale in California in the next hundred years’ or ‘this summer’s Atlantic hurricane season will most likely see more hurricanes in the Caribbean than last year’; it is on the basis of these rough and ready predictions and the historical record (and, of course, the extra-scientific assumption that the laws of physics will endure) that building codes in the relevant regions have changed in response.

Still, Maskin is on to something: most careless characterizations of science attribute far too many essential features to science.

Consider for instance, a definition of science that says a scientific discipline necessarily relies on experimentation and produces law-like statements about nature. The former would exclude cosmology, the latter biology. (Rosenberg and Curtain have been careful enough to not talk about laws or experimentation in their description of the ‘essential’ features of science.)

The model of science that Rosenberg and Curtain work with is, unsurprisingly enough, based on physics. Furthermore, the examples they use–predicting the orbit of a satellite around Mars, the explanation of chemical reactions in terms of underlying atomic structure, predictions of eclipses and tides, the prevention of bridge collapses and power failures–are derived from the same terrain.  In general, there seems to be much consensus that a putative candidate for scientific status succeeds the more closely a description of it matches that of paradigmatic theoretical and experimental physics. As this similarity fades, more work has to be done to include that discipline in the scientific cluster.

It is still not clear to me that economics is a science. But that is not because it fails to meet some ‘essential feature’ of science; rather, it is because we still lack a complete understanding of what makes a discipline a science.  There is a persistent difficulty of the characterization problem in the philosophy of science: most definitions of science–as any undergraduate in a philosophy of science class quickly comes to realize–fail to do justice to scientific practice through history and to the actual content of scientific knowledge.

The debate about whether economics is a science is most interesting because it shows the prestige associated with scientific knowledge; a successful classification as a science entails greater acceptance and entrenchment of its claims, and concomitantly, greater support–possibly financial–for its continued practice.

In the marketplace of competing knowledge claims, this is the truly important issue at hand.

5 comments on “Is Economics a Science?

  1. Well, philosophers can’t even agree on what science is (e.g. Popper v. Kuhn), so I wouldn’t expect folks to agree on whether borderline cases are science.

    That said, I tend to agree that predictability can’t be the end of it. I tend to fall into the falsifiable view – does the study lead to something that can be tested and falsified? If so, it’s a lot more likely to be science.

  2. Samir Chopra says:

    Michael,

    Thanks for your comment – good to see you here. Predictions *could* be built into the model – the discipline must make predictions that could be tested and falisified etc. But I agree the lack of agreement is unsurprising given the basic problem with definition.

  3. I view it as a form of sociology – noting that both economics and sociology have been duly subjected to the quantification and reduction to mechanisation that we attribute to ‘scientific method’.

  4. Krishna Kumar says:

    I think the distinction (if you are convinced there needs to be a distinction in the first place i.e.) should be clearly along the lines of social and natural sciences and subject of study rather than based on the old verifiable observation point. The problem with the verifiable-observation-and-subsequent-modification-to-the-theory angle is that you will never have an accurate definition of what constitutes an observation and how subjective it is, even in the natural sciences.

    The only real point and the way definitions should be structured I think, again, if you really want to make a distinction, is that the fundamental subject of study in natural sciences, the particles, once they are defined as a uniquely identifiable group (whichever level of granularity you want to go to, depending on the particular branch of natural science) behave uniformly over any length of time under the same conditions. An electron is an electron or a top quark is a top quark, irrespective of which electron or which top quark you are looking at. And, even weather and other more complex models have the same fundamental building blocks. Then on, it is a matter of complexity. (While on the topic, the Quark and the Jaguar is an excellent book.)

    It is arguable of course that social sciences are also based in a way on the same building blocks, but (luckily perhaps) as long as we can’t precisely pin down human behaviour down to the molecule so to speak, we will have the distinction of natural and social sciences.

    The problem with a lot of these opinion pieces (both the Rosenberg-Curtain one and the Maskin one) is that the motivation seems to be to advance your thesis rather than to attempt clarifying things. If they keep at it for a while, they will ensure the successful merging of social and natural sciences, at least according to their definitions. One as entirely predictable as the other.

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