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> Suppose we get rid of economists and their models; then what do we use in their place to guide policy? Our intuition? Controlled small-scale experiments? Eth

> Suppose we get rid of economists and their models; then what do we use in their place to guide policy? Our intuition? Controlled small-scale experiments? Ethnography? Historical analysis? Debate among stakeholders? Why do decisions have to be justified using mathematical models? Especially when those models have to be simplified to the point where they're really just "stories" (Paul Krugman's words) about economies? Why not just tell the stories in English? In a number of fields where the object of study is particularly complex - biology and medicine being notable examples - mathematical models are ineffective. What makes you think the economy is different?

QuesnayJr 7y ago
Because you can say things in mathematics that are hard to say in English. The stories are clearer when expressed in mathematical form. It's harder to bullshit your way through. Before the 70s/80s, everyone was somewhat confused about what they were arguing, particularly in macroeconomics. Now it's much clearer the kinds of claims we are making about the world.
- soVeryTired 7y ago
  I absolutely disagree. As an exercise, try translating a representative agent / rational expectations / DSGE model into English and see how ridiculous it sounds. Mathematics might force you to be internally consistent, but it also forces you to make bad assumptions. You can prove anything by reasoning from a faulty premise.
  - QuesnayJr 7y ago
    Everyone who stays away from writing down a mathematical model is either confused themselves, or trying to confuse their readers. The advantage of a model with a representative agent, or rational expectations, is that I can see the assumption right there. They made it perfectly clear. They didn't try to fool me with a barrage of words. If I think their explanation is wrong because people are irrational, or because the agent heterogeneity is important, I can take their model and show how it falsifies their results. And one important thing we learned from those models (which I agree do not work) is that we don't get business cycles from irrationality or from agent heterogeneity -- we get them from the failure of markets to clear. Economists were confused about this for like a century, and thanks to mathematical modeling it became clear.
    - soVeryTired 7y ago
      > Everyone who stays away from writing down a mathematical model is either confused themselves, or trying to confuse their readers. That seems like a profoundly narrow viewpoint to me. I mean maybe you're right in the sense that there might be an equation that governs the evolution of the universe, but are you really saying mathematical models are the only way to approach research? If so I strongly recommend you do some scientific reading outside of economics and physics. I think most interesting phenomena in the world are too complex to capture in mathematics. Physics is a profound outlier in that regard. > And one important thing we learned from those models (which I agree do not work) is that we don't get business cycles from irrationality or from agent heterogeneity -- we get them from the failure of markets to clear. Economists were confused about this for like a century, and thanks to mathematical modeling it became clear. I really don't think that's clear at all.
      - QuesnayJr 7y ago
        I have done plenty of reading outside of economics and physics, as well as reading in the history of economics. It is clear to me that economics stumbled around in the dark until the mathematical modeling revolution. There are very few interesting phenomena in economics that we can't capture in a model.

QuesnayJr 7y ago

Because you can say things in mathematics that are hard to say in English. The stories are clearer when expressed in mathematical form. It's harder to bullshit your way through. Before the 70s/80s, everyone was somewhat confused about what they were arguing, particularly in macroeconomics. Now it's much clearer the kinds of claims we are making about the world.

soVeryTired 7y ago
I absolutely disagree. As an exercise, try translating a representative agent / rational expectations / DSGE model into English and see how ridiculous it sounds. Mathematics might force you to be internally consistent, but it also forces you to make bad assumptions. You can prove anything by reasoning from a faulty premise.
- QuesnayJr 7y ago
  Everyone who stays away from writing down a mathematical model is either confused themselves, or trying to confuse their readers. The advantage of a model with a representative agent, or rational expectations, is that I can see the assumption right there. They made it perfectly clear. They didn't try to fool me with a barrage of words. If I think their explanation is wrong because people are irrational, or because the agent heterogeneity is important, I can take their model and show how it falsifies their results. And one important thing we learned from those models (which I agree do not work) is that we don't get business cycles from irrationality or from agent heterogeneity -- we get them from the failure of markets to clear. Economists were confused about this for like a century, and thanks to mathematical modeling it became clear.
  - soVeryTired 7y ago
    > Everyone who stays away from writing down a mathematical model is either confused themselves, or trying to confuse their readers. That seems like a profoundly narrow viewpoint to me. I mean maybe you're right in the sense that there might be an equation that governs the evolution of the universe, but are you really saying mathematical models are the only way to approach research? If so I strongly recommend you do some scientific reading outside of economics and physics. I think most interesting phenomena in the world are too complex to capture in mathematics. Physics is a profound outlier in that regard. > And one important thing we learned from those models (which I agree do not work) is that we don't get business cycles from irrationality or from agent heterogeneity -- we get them from the failure of markets to clear. Economists were confused about this for like a century, and thanks to mathematical modeling it became clear. I really don't think that's clear at all.
    - QuesnayJr 7y ago
      I have done plenty of reading outside of economics and physics, as well as reading in the history of economics. It is clear to me that economics stumbled around in the dark until the mathematical modeling revolution. There are very few interesting phenomena in economics that we can't capture in a model.