Sunday, June 3, 2012

the weaknesses of analogical reasoning

This article, shared recently by Marginal Revolution, got Anti-Mankiw's blood boiling, for all the wrong reasons. The core issue was the defense of mainstream economics through the use of particular analogies that we believe are fundamentally flawed.

As we explain elsewhere, analogies are often a deceptive way of explaining the core analytical framework of a concept, because an analogy between A and B is only as good as the likeness between A and B. It seems better to start off by explaining the core logical framework from within the language of economics, instead of alluding to its likeness to other sciences. Unfortunately, that is not the approach taken in Mankiw's textbook -- as early as chapter 2 he analogizes the study of "economic science" to physics.

What are the specific offenses that the article makes?

1. Saying that economics is like other sciences, such as medicine. As the article states,
"Galbraith’s and Varoufakis’s worry [that economics has become too mathematical] has been around for 20 years, says Grossman at Princeton. “It comes and goes. It particularly comes when economic times are hard, when it appears that the old way has let us down.” Did the old way let us down? “No,” he answers, “which is very different from saying we know everything. … I don’t think medicine has let us down because there are diseases we don’t know how to cure.”"
Economics is not like medical science. In medicine, all hypotheses go through rigorous empirical testing before they can be accepted by the field, and even at that point, caution is exercised when it comes to making generalizations. Also, in medicine, we don't have to make assumptions about how cells or molecules behave, while with people, making such assumptions is not only very important, but subject to a much wider menu of possible interpretations, often with dramatically different, and political, implications.

2. The idea that there is a "free market" in economics departments, so that graduate students can pick the ones that seem to be offering the most realistic version of economic theory out there. As the article states,
"Harald Uhlig, chair of the economics department at the University of Chicago, another of the No. 1-rated economics graduate schools in the U.S., offers a kind of a model of his own. In an e-mail, he writes: “Above all, I do not believe in central planning. What is true in private markets is true in PhD education as well: It is good to see different places try different approaches, to let the PhD students decide where they want to be educated, and to let the marketplace for future scientists decide what works and what does not. I am sure that if the new PhD program in Athens is successful and produces the top young economics researchers of the next generation, many other PhD programs will take notice.”
Such a comment ignores the very real differences between top graduate programs and lower-ranked schools in terms of prestige -- something that often goes hand-in-hand with support for the status quo and getting top (influential) jobs, and refraining from any radical criticism of the current paradigm (which is what economics needs at this point).

The thing that concerns us most about these analogies is that, for the casual reader who doesn't know much about the field of economics, it is very easy to take these analogies for granted. Without any rigorous knowledge of the field, understanding is made easier by analogy.

But for those who have an advanced understanding of the field, the weakness of the analogical approach is clear. We are, indeed, actively promoting ignorance by taking such an approach, instead of being honest about our flaws and about the structure of graduate education.


  1. I always cringe at the analogies between the theory of evolution and the political basis for capitalism. Krugman espoused this exact position.

  2. I find the analogical reasoning extremely annoying when studying economics as well (I've just finished by undergraduate degree). For example, when learning about the make-believe world of perfect competition, our lecturer said that,
    "we don't actually believe in perfect competition, but it's a benchmark against which we judge more realistic market structures. For example, think of it as analogous to physicists assuming away friction when modelling the motion of an object along an inclined plane".

    However, this comparison between economics and physics is completely bogus, and is hugely offensive to a proper science like physics that actually follows the scientific method, is rigorous and whose theories have infinitely greater predictive power and internal consistency.

    I know this is quite a bleak outlook but I don't think graduate training in economics serves any purpose tbh apart from indoctrinating the next generation of economists in neoliberal dogma. There isn't a free market in economic ideas, because if you try to pursue ideas outside the mainstream, you're not on an equal footing to those who follow the mainstream neoliberal research program. I think it's about time economics as a subject went the way of Astrology.

    An example of how ideologically biased economists are is when my macro lecturer was talking about a talk given at my university by a heterodox economist talking about evolutionary economics. His tone was so disparaging, as if the guy didn't know what he was talking about, and he made an off-hand remark about how he was "one of those old Keynesian lefties" as if being left wing makes your views wrong. This told me how poisonous the subject has become, and why I decided against doing a masters in it, even though I was planning on it at the start of my degree. I simply couldn't carry on being part of this right wing neoliberal machine that has devasted the world economically, ecologically and morally.

    1. "we don't actually believe in perfect competition, but it's a benchmark against which we judge more realistic market structures. For example, think of it as analogous to physicists assuming away friction when modelling the motion of an object along an inclined plane".

      Competent physicists do not assume away friction. My intro textbook (Tipler) introduces friction in chapter 1. Feynman talks in _Surely You're Joking Mr. Feynman_ (or possibly the sequel) about how Brazil was teaching cargo-cult physics by leaving out friction.

      This shows how sick economists are. They're aping physicists, but they don't even know how physics works -- they're aping *incompetent, unscientific* physicists, the worst sort.

    2. "I think it's about time economics as a subject went the way of Astrology. "

      Agreed. We need a new name for the replacement -- "theory of wealth and money"?

  3. Redshift: great point. When econ profs use the physics analogy, I think a great way to counter back is to ask, "do molecules think for themselves?". The fact that they don't means modeling molecule behavior is far less risky than modeling individual behavior.

    I got into graduate work b/c I wanted to change how the profession thinks. I'm not so much interested in that anymore, although I am to a degree. Now I'm more interested in contributing to an alternative...

  4. I think you do a great job attempting to forge an alternative, but I really do think that the whole economics establishment is 100% corrupt, and most of the "research" being conducted is simply gobbledegook with the sole intention of protecting the rotten core from criticism. Mainstream neoliberal economists will say "Oh you've got a poor understanding of the frontiers of research, why not read some of the academic papers?".

    They say this because most of academic economics is complete pseudoscience, using archaic mathematical concepts and applying them in totally inappropriate ways. It makes as much sense as a 3 year old doodling on a page absent mindedly. However, because economic research is so unfathomable that people don't know how to proceed to criticise it, which again protects the centre (although blogs like yours do a very good job).

    My opinion is that forging an alternative is not really possible, and the best thing that people opposed to the neoliberal hegemony can do is be more explicitly anti-economics, because the subject is responsible for most of the morally abhorrent policies being pursued by governments around the world. I don't see why the other social sciences and humanities subjects cannot then take over the issues that economists look at now, like production, distribution and allocation of resources. I have no doubt they'd do a much better job than economists, mainly because those disciplines haven't been taken over by corporate interests.

    I long for the day when governments stop funding this pseudoscience, and tell the corporations and big businesses that if you want to produce the next generation of economists to do your bidding, fund private colleges yourselves. This will have the added benefit of helping the government reallocate funding to the social sciences that have been chronically underfunded, and also will stop all those talented mathematicians and physicists who waste their talent by enrolling in graduate programs in mainstream neoliberal economics at Ivy League colleges.

  5. "An example of how ideologically biased economists are is when my macro lecturer was talking about a talk given at my university by a heterodox economist talking about evolutionary economics. "

    One of the problems with evolutionary economics, I find, is precisely the opposite. Evolutionary economics *should* be studied as a science. That is, there should be an expectation that meaningful policy implications are a long way off. The problem I have with evolutionary economics is precisely the opposite. They use evolutionary models to study market structure over time when evolutionary concepts will have clearly contributed to the creation of market structures in the first place. In this sense, I find evolutionary anthropology do a much better job of linking scientific theory to economics.

    The problem is actually much more apparent in other social sciences. At least in economics it does have an emphasis on deduction, albeit deducing relationships from a crude view of the world. I saw one economist claim economic models were works of art. He was defending them!

    Sociology, for example, can, in the rare paper, model human behaviour, but by-in-large is much more romantic than the most fanciful economic theory. To say sociologists have not had an impact on policy ignores the way public policy has been going over the last twenty years. Their work is extremely conservative and theory tends to be used to justify their existence.

    I kind of agree with you, but think the problem extends well beyond economics and even encompasses many of the physical sciences now; medicine, climate change, asteroid mining. Just read Nature or watch a TED lecture. Nothing but speculation. Academia is now big business, and so too are publishers. If you cannot show relevance of your work, you do not have a future. I guess Anti-Mankiw is claiming economic theory is partly to blame.

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