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I once sat in on a friend's final year economics course. They talked about the "gravitational model" of economics, that the amount of trade between two economi

I once sat in on a friend's final year economics course. They talked about the "gravitational model" of economics, that the amount of trade between two economies is proportional to the product of the size of the economies each raised to some power, divided by some power of the distance between them. They showed a best fit of the 5 parameters to under a dozen data points and it looked rather awful. (I am not sure how well defined those variables are). Without any theoretical justification it seemed like a model stolen at random from physics that didn't fit well. I've also read a published economic paper written in terms of measure theory, where it was clear the author did not understand measure theory at all. The ideas were misapplied to a simple problem in a way that made it sound very difficult. Admittedly this is partly the fault of mathematicans who teach measure theory as statistics; while you can use that model it makes things very complicated and you almost surely don't need to deal with infinities in most real problems, let alone non-measurable sets. This arm of economics trying to ride the coattails of prestige worn by maths and physics is void of meaning.

smhcf8 9y ago
You seem to at least have some personal experiences/familiarity behind your criticism, unlike almost everyone in this thread. So here's a chance to substantiate your claim. Here is a paper that was recently published in the Journal of Economic Theory https://dl.dropboxusercontent.com/u/17516137/RapidWeaverSite/resources/papers/extremal35.pdf https://dl.dropboxusercontent.com/u/17516137/RapidWeaverSite... This was a co-authored publication of an economist and a political scientist (at the University of Rochester). It's one of their several co-authored pieces; and it was published in a good field journal, but not a top general-interest journal. It has so far received a couple of cites from papers on the same topic. My point is, this paper is fairly "standard" for contemporary economic theory. It also happens to use a decent amount of measure theory. Now, I will personally venmo you $200 if you are able to find a single mistake or "abuse" of measure theoretic concepts in that paper in the following sense: a measure-theoretic theorem, definition, or proof technique was unnecessary for mathematical purposes, and you can demonstrate why that's true by writing an alternative proof, with the same generality but without such a concept. I'm not baiting you, I'm genuinely curious to see if you or anyone else in this thread can do it, because I had taken plenty of measure theory in my PhD days, and this paper's usage of it seems perfectly on point to me. I'm also using it as an example because the authors' language is very clear and meticulous, and you shouldn't have trouble accessing that paper without knowing economic jargon. I can also link you a few other random economics papers if you want. Alternatively, you could admit your disparagement of economists' intellectual ability, and intellectual honesty, was perhaps misplaced.
- soVeryTired 9y ago
  Solovay showed that assuming the negation of the axiom of choice, there exists a model of real analysis where all sets are measurable. So really you only need measure theory if the paper depends on the axiom of choice in some fundamental way. But would you really trust an economics paper that depended on the axiom of choice? For me, a good analogy is with engineers and real numbers. Engineers use real analysis all the time. But the results of an engineering paper should not depend on the definition of a real number, nor should the engineer care. Edit: Hamming made the point better than I can: "Does anyone believe that the difference between the Lebesgue and Riemann integrals can have physical significance, and that whether say, an airplane would or would not fly could depend on this difference? If such were claimed, I should not care to fly in that plane".

smhcf8 9y ago

You seem to at least have some personal experiences/familiarity behind your criticism, unlike almost everyone in this thread. So here's a chance to substantiate your claim. Here is a paper that was recently published in the Journal of Economic Theory https://dl.dropboxusercontent.com/u/17516137/RapidWeaverSite/resources/papers/extremal35.pdf https://dl.dropboxusercontent.com/u/17516137/RapidWeaverSite... This was a co-authored publication of an economist and a political scientist (at the University of Rochester). It's one of their several co-authored pieces; and it was published in a good field journal, but not a top general-interest journal. It has so far received a couple of cites from papers on the same topic. My point is, this paper is fairly "standard" for contemporary economic theory. It also happens to use a decent amount of measure theory. Now, I will personally venmo you $200 if you are able to find a single mistake or "abuse" of measure theoretic concepts in that paper in the following sense: a measure-theoretic theorem, definition, or proof technique was unnecessary for mathematical purposes, and you can demonstrate why that's true by writing an alternative proof, with the same generality but without such a concept. I'm not baiting you, I'm genuinely curious to see if you or anyone else in this thread can do it, because I had taken plenty of measure theory in my PhD days, and this paper's usage of it seems perfectly on point to me. I'm also using it as an example because the authors' language is very clear and meticulous, and you shouldn't have trouble accessing that paper without knowing economic jargon. I can also link you a few other random economics papers if you want. Alternatively, you could admit your disparagement of economists' intellectual ability, and intellectual honesty, was perhaps misplaced.

soVeryTired 9y ago
Solovay showed that assuming the negation of the axiom of choice, there exists a model of real analysis where all sets are measurable. So really you only need measure theory if the paper depends on the axiom of choice in some fundamental way. But would you really trust an economics paper that depended on the axiom of choice? For me, a good analogy is with engineers and real numbers. Engineers use real analysis all the time. But the results of an engineering paper should not depend on the definition of a real number, nor should the engineer care. Edit: Hamming made the point better than I can: "Does anyone believe that the difference between the Lebesgue and Riemann integrals can have physical significance, and that whether say, an airplane would or would not fly could depend on this difference? If such were claimed, I should not care to fly in that plane".