Just a quick footnote to the economic man stuff. Talking about Wikipedia probably gives me a credibility problem, but the page I referred to yesterday to is actually pretty impressive, and has some good points worth mentioning.
"One problem with making the Homo economicus model more sophisticated is that sometimes the model becomes tautologically true, i.e., true by definition. If someone has a "taste" for variety, for example, it becomes difficult if not impossible to distinguish economic rationality from irrationality. In this case, the Homo economicus model may not add any new information at all to our economic understanding."
Indeed: anything can be rationalized. The whole sorry debate about economic man could probably be avoided if we understand that "the Homo economicus model" isn't supposed to add new information to our economic understanding. The economist's ultimate goal is not to figure out how people behave - that's just something we have to address along the way to describing things. Economic man is no more of an end than the super-supercomputer I invoked yesterday.
However, my favorite bit from the page is this nice little dig:
"These criticisms [of economic man] are especially valid to the extent that the professor asserts that the simplifying assumptions are true and/or uses them in a propagandistic way."
No argument here. Economics teaching is usually depressing. Why is the first thing students of economics see a supply and demand diagram? How does that help them understand what we're trying to do, what we assume? How, more importantly, is that value free? How can that separate economics from capitalism, money, markets? How can that be economics?
"It is primarily when targeting the limiting assumptions made in constructing undergraduate models that the criticisms listed above are valid."
Imagine hundreds, thousands of students come to you every year. You can show them why your subject is exciting, what it can do philosophically and practically, ask big questions, educate an astonishing number of diverse students, make the next generation of economists good scientists while allowing all normative opinion to flourish around the argument. You can take students with all preconceptions, with all beliefs, and send those students away in their diversity of thought as economists. The next generation of economists would have a fighting chance of being value-free, and the debate wouldn't be "us versus the economists", but just "us".
Hundreds of thousands of students do come to Econ 101 every year. We show them a supply and demand diagram and reinforce all prejudices. We present economics as an answer. How many minds do we lose? How can we tolerate the waste?
Showing posts with label surprisingly earnest. Show all posts
Showing posts with label surprisingly earnest. Show all posts
Friday, February 8, 2008
Who is economic man?
A provocative opening to this article attacking something called "economic man":
"Myth: Homo economicus is a valid assumption of human behavior.
Fact: Homo economicus is a fiction useful to right-wing economists."
"Economic man" would be too easy, of course; "Homo economicus" sounds more intellectual and somehow also more ridiculous. Anyway, if I pretend not to see the right-wing bit - what's a right-wing economist? - I think the fact is a fact and the myth is a fact too, and not just because defining a "valid assumption" is not quite as obvious as it seems.
The essay is actually pretty interesting, though obviously normatively motivated. It goes on to say:
"Specifically, social scientists believe that human behavior is often complex, imperfect, limited, self-contradictory and unpredictable. Homo economicus, however, is a greatly simplified model which assumes that individuals possess the following traits:
* Perfect self-interest
* Perfect rationality
* Perfect information"
I love that "human behavior is.... unpredictable"; the logical conclusion of that argument would be to abandon all social science, would it not? Let's take the long view and ignore that bit. Aside from that, as I've argued before, the perfect information trait has been scrutinized intently for a few decades, so it's probably an obsolete criticism. The rationality bit is, again, untestable, since what we mean by rationality is that some pattern that's to some degree predictable - whatever it might be - affects behavior.
The self-interest trait is the one that comes in for a lot of criticism, in the essay and generally. The most important myth to dispel right away is that "self-interest" means "cares only about things that materially affect me"; it means "cares only about things that I care about", which is delightfully tautological and more innocuous. We have a special definition of "selfish". I think what the critic really means is more in the spirit of the following, from Wikipedia (sorry):
"Economic man is also amoral, ignoring all social values unless adhering to them gives him utility. Some believe such assumptions about humans are not only empirically inaccurate but unethical."
There are two problems with that: one is the use of "unethical", which I'll save for another day, and the second is methodological. It's possible to write down a rational, self-interested "economic man" who will do anything. Literally anything can be "rationalized"; it's meaningless to say that it's "empirically inaccurate" to assume that "social values" give a person utility, because it's impossible to empirically answer that question one way or another. Economists seeking accuracy would, methodologically, model a person who acted in accordance with social values as if that person got utility from conforming to social values. Our rational, self-interested man has magically developed a social conscience!
Later in the original article, the author says (in direct contradiction to their earlier claim that behavior is unpredictable, by the way):
"Biologists recognize four levels of survival: the gene, the individual, the group, and the specie. All of them interact to produce the complex and often paradoxical behavior we witness in humans. The error of Homo economicus is that it focuses only on one level: the individual. It cannot explain why couples bear children (to promote genetic survival), or why soldiers often sacrifice their lives in war (to promote group survival), or why people practice charity (to promote human survival)."
Again, I can only plead that we recognize that whatever economists do or are perceived to do, their method of modeling people can explain anything, and I mean that as both a criticism and a compliment. Our method is neutral, our method is empty. Attack the normative interpretation of our conclusions. Attack the assumptions we make. Don't attack the method: you're shooting at thin air.
Let's do a thought experiment: imagine we had a super-supercomputer that could accommodate all the complexity we wanted, and imagine that our computer has also figured out how to perfectly model every single human being, and imagine that we believe it. Forget the fatalist implications and just ask: would an economist - who seeks to model choice and the allocation of scarce resources, to describe the world, to make predictions, and, ultimately, to inform - reject the computer? Would he reject the model? If he would, he is not a scientist: if the economist would reject it, then I'll let all the critics of economics attack him, because surely the only way to justify rejection of that gift would be because the model would generate predictions that the economist didn't like.
Economists should never make their "economic man" to suit their ideological goals. That's not science. We must make our "economic man" realistic but clear, acknowledge what he does and does not do, what he does and does not embody. He can be anything we want: we are therefore powerful, and must then be honest, if nothing else.
"Myth: Homo economicus is a valid assumption of human behavior.
Fact: Homo economicus is a fiction useful to right-wing economists."
"Economic man" would be too easy, of course; "Homo economicus" sounds more intellectual and somehow also more ridiculous. Anyway, if I pretend not to see the right-wing bit - what's a right-wing economist? - I think the fact is a fact and the myth is a fact too, and not just because defining a "valid assumption" is not quite as obvious as it seems.
The essay is actually pretty interesting, though obviously normatively motivated. It goes on to say:
"Specifically, social scientists believe that human behavior is often complex, imperfect, limited, self-contradictory and unpredictable. Homo economicus, however, is a greatly simplified model which assumes that individuals possess the following traits:
* Perfect self-interest
* Perfect rationality
* Perfect information"
I love that "human behavior is.... unpredictable"; the logical conclusion of that argument would be to abandon all social science, would it not? Let's take the long view and ignore that bit. Aside from that, as I've argued before, the perfect information trait has been scrutinized intently for a few decades, so it's probably an obsolete criticism. The rationality bit is, again, untestable, since what we mean by rationality is that some pattern that's to some degree predictable - whatever it might be - affects behavior.
The self-interest trait is the one that comes in for a lot of criticism, in the essay and generally. The most important myth to dispel right away is that "self-interest" means "cares only about things that materially affect me"; it means "cares only about things that I care about", which is delightfully tautological and more innocuous. We have a special definition of "selfish". I think what the critic really means is more in the spirit of the following, from Wikipedia (sorry):
"Economic man is also amoral, ignoring all social values unless adhering to them gives him utility. Some believe such assumptions about humans are not only empirically inaccurate but unethical."
There are two problems with that: one is the use of "unethical", which I'll save for another day, and the second is methodological. It's possible to write down a rational, self-interested "economic man" who will do anything. Literally anything can be "rationalized"; it's meaningless to say that it's "empirically inaccurate" to assume that "social values" give a person utility, because it's impossible to empirically answer that question one way or another. Economists seeking accuracy would, methodologically, model a person who acted in accordance with social values as if that person got utility from conforming to social values. Our rational, self-interested man has magically developed a social conscience!
Later in the original article, the author says (in direct contradiction to their earlier claim that behavior is unpredictable, by the way):
"Biologists recognize four levels of survival: the gene, the individual, the group, and the specie. All of them interact to produce the complex and often paradoxical behavior we witness in humans. The error of Homo economicus is that it focuses only on one level: the individual. It cannot explain why couples bear children (to promote genetic survival), or why soldiers often sacrifice their lives in war (to promote group survival), or why people practice charity (to promote human survival)."
Again, I can only plead that we recognize that whatever economists do or are perceived to do, their method of modeling people can explain anything, and I mean that as both a criticism and a compliment. Our method is neutral, our method is empty. Attack the normative interpretation of our conclusions. Attack the assumptions we make. Don't attack the method: you're shooting at thin air.
Let's do a thought experiment: imagine we had a super-supercomputer that could accommodate all the complexity we wanted, and imagine that our computer has also figured out how to perfectly model every single human being, and imagine that we believe it. Forget the fatalist implications and just ask: would an economist - who seeks to model choice and the allocation of scarce resources, to describe the world, to make predictions, and, ultimately, to inform - reject the computer? Would he reject the model? If he would, he is not a scientist: if the economist would reject it, then I'll let all the critics of economics attack him, because surely the only way to justify rejection of that gift would be because the model would generate predictions that the economist didn't like.
Economists should never make their "economic man" to suit their ideological goals. That's not science. We must make our "economic man" realistic but clear, acknowledge what he does and does not do, what he does and does not embody. He can be anything we want: we are therefore powerful, and must then be honest, if nothing else.
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