This is an interesting, if rather flawed, blog post. From what I can see, he says this (skip bullet points if you have read it):
- Mathiness is truthiness, but in the way that putting down any mathematical symbols lends an air of intelligence and truth to an argument, for many people, especially those who don't or can't take the time to understand the argument logic.
- Then he explains how economics data are not as easy to construct with universal agreement as with, say, physics (temperature). Agreement on practical action is hard when contrary frames and interpretations appear valid.
- He then mentions how this might be a problem for defining capital and other constructs for Piketty, but without any useful argument beyond this assertion.
- He then contrasts Feynman's integrity, trying to disprove his own work to make it better, to economist George Stigler's rhetorical style of conviction, ignoring contrary arguments, and playing the polemicist.
- He then mentions Isaiah Berlin's distinction between foxes who know little about something , and hedgehogs who know one big thing.
All these are interesting frames by which to compare and contrast various things. Yet his analysis, after bringing in all these ideas, is just to say that economics needs both careful analysis and effective rhetoric. Well, duh, but how does this tie into all the great setups he's made so far?
And mathy people are good at neither rhetoric nor polemic? But surely, if you're afraid of these people, they would be a mathy person who is using rhetoric to undermine the real philosophy and logic that should - pace Plato - be informing the argument.
It's a post full of story and setup, but as yet, signifying nothing.
It's an attack on Piketty without any substance, best I can tell. The problem with any attack on Piketty is that you can test his theory. Ironically, Bill Gates took issue with Piketty's famous r > g formula with at least one predicate he would add. He didn't extrapolate on it (he should if he wants to make a real argument), but at least he put something down. Kay didn't even bother with going that far. He should.
His point is that there is a good way to use math, which is to clearly state assumptions and definitions and then derive the result, and a bad way to use math, which is to avoid clearly defining objects that math operates on. It helps avoid criticism, but makes the whole exercise rather useless.
One of my economics professors in undergrad used to say, when teaching Milton Friedman's monetary theory: "Given these assumptions, only GOD could reach a different conclusion." And then he would cackle absurdly. The point was that the ideology was hidden in the assumptions, and economics as a discipline was a) corrupted by ideology and b) using mathiness to obscure that.
Economics often mixes up normative and positive stances but at least it makes it easy to separate them by using models. It makes the assumptions explicit. You can then take the models and relax or change the assumptions and see Evart changes. That's why and where macroeconomics approaches a science.
Science involves experiments. The best economists can do is take a few poorly recorded historical measurements of incomprehensibly complicated systems and try to force-fit them to their simple models.
A lot of social science, including economics, does not involve experiments. Perhaps you want to argue that social science is not science, but if so, I personally find your definition of science a bit restrictive.
Nope, the article is not about that. It is one thing to clearly state assumptions and derive the conclusions from there (which is what your professor seems to have done). This is not "mathiness": indeed, this is exactly how theory is supposed to work -- as long as the assumptions and the logic are clear, he can disagree with the assumptions and this way argue against the results.
It is quite another thing to replace assumptions by handwaving, in which case the point of math and logic is lost, and the argument becomes non-falsifiable. This is what the article calls "mathiness" and argues against.
Every careful person equipped with a reliable thermometer will make the same reading of temperature. There are alternative scales, Fahrenheit and Celsius, but both record the same thing...
to
Economics is genuinely harder. National income is a more complicated concept than temperature, and there are plausible alternative sets of rules for calculating it. Serious minded statisticians have spent many years discussing these issues, and there is now a UN-sponsored standardised system of national accounts.
But it is easy to write a mathematical symbol without giving thought to what observable fact in the real world corresponds to that symbol, or whether there is such an observable fact at all.
But isn't that exactly how we settled on the truth of temperature? Years of debate about what the right constructs for defining temperature mathematically are?
Yes and no. There's no single god-given way to measure temperature (though the 0-point seems clear), but once you have a scale, comparing the temperatures of two liquids is straightforward. On the other hand, a symbol like GDP is really a mix of thousands of inputs sampled using a variety of techniques and adjusted according to dozens of criteria like inflation and hedonics. Comparing GPD over time in a single country is crude, modeling GDP across countries is nothing at all like calculating how quickly water heats up compared to mercury.
It should be noted that a "temperature scale" is a pretty non-obvious thing. The idea that the temperature we call "ten degrees" is as much colder than "twenty degrees" as that is colder than "thirty degrees" is something you'd never figure out without getting as far as the 18th century.
Even the concept of "temperature" is not obvious. Give someone a hot piece of bread and a hot piece of metal and the metal seems hotter even if they're at the same temperature.
Statistical mechanics is a subject for which it is very hard to pin down the conceptual foundations. To read a thermometer I need to be sure it has reached "thermal equilibrium" with the object being measured. But how do you define thermal equilibrium in terms of underlying mechanical ideas? How do we identify the mechanical systems to which the concept of temperature and thermal equilibrium can be meaningfully applied? See http://philsci-archive.pitt.edu/2691/1/UffinkFinal.pdf We would be accusing statistical mechanics of 'mathiness' were it not the case that we know how to make it work for very many systems of practical interest. The main problem with economics is that it does not work as often.
Good points. I think the hidden terms here are "ratio variables" vs "interval variables". It's not obvious that 200 degrees (Kelvin) is twice as hot as 100 degrees. But almost everyone is going to agree that water at 300K feels hotter than water at 280K (though this may not work across materials, as you note).
What we can do with our temperature scale is build a model that says every time we convert n liters of oil into heat and direct it at x liters of water we get a change of temperature of y degrees. Reliably, and with small margin of error.
We can't do this with GPD, and if we declare that a 10% increase in education spending will lead to a 5% increase in GDP over 15 years, we don't have a testable scientific model, we have a guess based on our interpretation of extremely messy data.
Except groups exchanging capital are still an GAI-complete system, unlike atoms - even if they behave predictably, they can start doing weird things completely at random. Also, atoms themselves don't have equal voting or influence rights to change the way we compute temperature when it suits them.
True, but irrelevant. The definition of temperature (average kinetic particle energy) means it exists. Conversely, Absolute Hot[1], is an open question.
Irrelevant to what? The poster claimed that there was a real thing in a physical reality. If that is true, shouldn't we have observed it before? As the statement stands it claims as absolute reality something which no one has ever seen.
Ok, so we've never seen something to be exactly 0K. We've probably also never seen anything to be exactly 3.14159K. That doesn't mean objects with temperature of exactly 3.14159K are impossible, neither that we should assume they don't exist until you point out an example.
Temperature scale is a good model that maps the territory quite well. There is nothing to suggest it will suddenly stop working at 0K, if it works very well even as we get closer and closer to absolute zero.
Contrast with most economic models which as maps correspond to territory in a similar way the map of China corresponds to the Middle Earth - there are trees and not trees, you have to turn it around to make the sea be on the proper side, and... that's about how much it matches. Be wary of zooming too much in, lest you get eaten by an Orc.
It may be a good model, but that is not what the poster claimed. The poster claimed that is was an aspect of a real, physical reality. There is no evidence of that.
In fact, there is a good argument that 0k is unachievable [0].
》 If that is true, shouldn't we have observed it before?
No. The concept of temperature is based on the bulk interactions of matter due to the motion/collisions of atoms and molecules relative to an inertial reference frame. A frame that usually has to exist outside of the system for temperature to have practical meaning so it is a concept that by definition has an absolute zero, even if we haven't observed it yet.
In this case, absolute zero really means zero motion relative to the instrument measuring the sample so it is possible for a Type 1+ civilization to build a planet sized (or bigger, don't know how the math works out but it probably has something to do with constricting atoms to a precision within a planck length) laser or other electromagnetic trap to cool some nontrivial number of atoms to absolute zero like those used for Bose-Einsten condensate experiments.
Wrong. Nonsense invocations of nomenclature and pretentious obfuscations aside, your explanation came after the fact. When temperature scales were being constructed, neither thermodynamics nor atomic theory had been at the state you presuppose. What you state are not givens, they are conclusions of theories and explanations of the observations in terms of them. To say that temperature must by definition have an absolute zero isn't saying anything. Where did this definition come from? What is heat that temperature measures (yes, heat, not temperature)? Neither Fahrenheit nor Celsius knew. Current kinetic theory explains heat as exclusively the motion of microscopic things (not just atoms, btw) and it thus follows that the absence of motion must mean the absence of heat. In the 17th century, you might be telling us that absolute zero is complete dephlogistication. But why should temperature have an absolute zero? Without your theory of heat, or at least some intuition of it that frames heat as a quantity and cold merely the absence of heat, you have no reason to claim that temperature has a lower bound.
You really need to understand the order of dependence of explanations.
Let me turn this around. What do you think the hypothesis is, and how would you know if you've succeeded? Do not use the term "absolute zero" because you think that is a hypothesis, and not a definition.
No. The definition of Absolute Zero is zero kinetic energy of the particles of a substance. You've been complaining that this definition is somehow a hypothesis, or otherwise suspect because it has never been observed, which I've said, was irrelevant, we can calculate it. It's not hard. It's junior high physics. What's the kinetic energy of something that has stopped? It's zero.
Your position is absurd. It's equivalent of saying, that distance is an unproven hypothesis, (which literally doesn't make any sense, because that's not what the word means), or perhaps more charitably a suspicious concept because we've never measured anything with zero distance between two items, because the closest two particle can get is planck length.
I'm not trying to be mean, but what you've been saying is pure gibberish.
Whether a scale has a zero is something that is decided after the fact. Whether it is "fundamentally important" is, again, dependent on the state of the theory it is bound up with and the result of.
Temperature is one thing, but without knowing the air pressure you couldn't even cook an egg properly.
Assuming unstated conditions, like normal air pressure, is just as well an entry point for error if you want to reliably describe the assumed state of things.
With temperature we know what feeling each measurement corresponds to. When a politician ernestly does everything he can to raise the GDP per capita of his country often he is not aware of what real world consequences there will be. E.g. In China ten years ago everyone had motorbikes. Ten years later many families have cars but the roads are stuck in gigantic traffic jams and the the sky is covered in smog, and rivers covered in muck. GDP per capita and median incomes are going up, but is life getting better where people are getting more fulfilled and more contented?
When you get into engineering one finds a strong caution to beware of optimizing the metric at the expense of the process. In your instance, GDP is up, median quality of life is down. Far as I can tell ordinary economists are totally blind to this.
Eh, there are Nobel laureates who work down the hall from each other who cannot agree on the definition of basic macroeconomic concepts such as what constitutes a "bubble" or whether "market failure" is even a valid concept to begin with.
This seems to be closely related to Feynman's "Cargo Cult Science", the use of the form and mannerisms of hard science to lend legitimacy to research or opinions that actually lack evidence.
Mathematical descriptions of things are fundamentally different from "truthy" arguments. Because once the math is laid down it stands on its own, independent of what anyone says about it. Whereas a truthy argument has no facts to stand independent of the argument because the facts themselves are false.
I'm no economist, but I am a mathematician, and I'd guess the problem isn't that people are trying to use math to knowingly give false credence to plainly ideological ideas, but rather that the mathematical skills of those who listen are too weak to isolate the problems in the arguments. I would hope economists are better than that, but I know politicians are not.
Part of it is about skills. Part of it is about things like making questionable connections between what is actually mathematically shown in the model, and what is claimed in terms of real-world relationships. Of course this is much easier to do when they don't clearly define how exactly real-world objects translate into the model :)
This is a political argument in the economics profession. Beyond the obvious points that math/data can be used to obscure weak arguments and that idealogical binders are bad for clear thought, Romer is simply attacking his political opponents. Oddly going after George Stigler - a Nobel winner who died 25 years ago who Robert Solow said "was never an ideologue."
Neither Kay nor Romer are the clearest writers but I think Romer was clearly attacking Stigler (as well as Lucas and others at Chicago) and Kay was just repeating what Romer said. See this:
I don't have access to Stigler's 1955 paper. It would be interesting to know what he was talking about but putting him in opposition to Feynman seems pretty harsh. It makes it sound like Stigler is a proponent of idealogical thinking and that's how he practiced economics.
People give a lot of authority to mathematics, because mathematics is immensely powerful to explain the natural world. This unfortunately leaves the opening for charlatans to do fake math and lend their garbage research a completely unwarranted air of legitimacy.
> attention given to the work of Thomas Piketty, with serious questions raised about the relationship between his data, his theory and the political stance which motivates his work.
Yes, you see, there are ideologically-driven economists like Piketty, who have a political stance. Then there are are the fair, neutral, unbiased economists who disagree with Piketty, who are only motivated by the search for the truth.
Truthy economists, you mean? Aha, the author must be such a neutral economist, a Fair and Balanced writer, a fine man! I don't need any substantive arguments from such as he. I'll take him at his fine gentlemanly word!
> Then there are are the fair, neutral, unbiased economists who disagree with Piketty, who are only motivated by the search for the truth.
There is no such thing as truth in Economics. There's not even a defined goal. Creating a mathematical model of how 7 billion people behave in a global economy is impossible.
You're always going to have to simplify your model enough for it to be useful, as the expense of something. That compromise is your bias. Economists always make assumptions about something, and those assumptions are always driven by some sort of world view.
Not to mention, the other part of economics is deciding what policies or actions should be taken. Do you optimize for economic growth? For happiness? To reduce inequality? To eliminate poverty? Maximum employment?
Other sciences describe things which can be replicated, or things which are (more or less) concrete. Economics can't be a concrete, truthful science because people are react to their environment, which is ever changing and will never be the same at 2 points in history. And everything affects human behaviour, from the weather to things like religion which aren't exactly concrete...
> Not to mention, the other part of economics is deciding what policies or actions should be taken. Do you optimize for economic growth? For happiness? To reduce inequality? To eliminate poverty? Maximum employment?
And if that's not difficult enough, you have to assign time-values to all of these. E.g. reducing inequality today might lower growth in 20 years.
Out of genuine interest, which economists would you recommend if one wanted to read the works of economists who are only motivated by the search for the truth?
Just get a microeconomics textbook and a price theory textbook. Hal Varian's Intermediate Microeconomics is probably best if you know calculus. Undergraduate macro bears very little relation to what economists believe and macro is a mess besides. Olivier Blanchard, former director of the IMF wrote an article on the state of macro, pronouncing it good just before the Great Recession. The field has barely moved since then. Macro is an intellectual monoculture that's not going anywhere. I personally am partial to Scott Sumner, who blogs at the Money Illusion abd is a market monetarist.
Parable of the Polygons[0] is another example of mathiness, where math is used to dress up a political message. The basic idea is simple and intuitive: people like diversity, but also don't like to be in the minority (e.g. they would like a 60/40 ratio of people of the same race to them vs people of different races). But when everyone applies this logic then you get completely homogenous regions.
The mathiness comes through the fact that the simulation is nothing like real life (e.g.people care about far more than their immediate neighbors) and yet the claim is that tweaking the parameters of this model gives some intuition about the quantitative real life effect.
What mathematical models do: provide ad-hoc support. It is better to call them out for what they are: ad hoc explanations do not contribute to sciences.
All scientific explanations are fundamentally ad hoc. We get scientific facts through falsifiable models based on evidence.
It’s the same in economics, but economics is a field that is both complex (informationally) and complicated (incidentally), so our models aren’t very good. Often they’re only falsifiable in theory, because a practical assessment would be too costly.
I have not heard anyone from Philosphy of sciences saying "all scientific explanations are fundamentally ad hoc". In fact, Adolf Grunbaum studied the nature of Adhoc explanations. Even Imre Lakatos claimed that prima facie ad hoc (those from the protective belt) can end up being non ad hoc.
What I have in my mind when I said mathematical models provide ad hoc suport is this. Today, it is consensus in the philosphy of sciences that there are two kinds of confirmation of a theory: confirming instance vs positive instance. Mathematical models generate "positive instances". A non-adhoc hypothesis generates confirming instances, a special type of positive instances. For more, pp. 61-62, Larry Laudan's "Science and Relativism: some key controversies in the philosophy of science.
Lets look at a hypothesis that says "All swans are white". One keeps on doing field work, saying that 1001th swan is white, 1002th swan is white, etc. All these field reports are "positive" instances. Such field reports don't add much.
We differ on our definition of “ad hoc”. I wanted to convey the fact that scientific explanation is just that—explanation. The basis of science is the creation of mathematical models to approximate phenomena that we observe.
- Mathiness is truthiness, but in the way that putting down any mathematical symbols lends an air of intelligence and truth to an argument, for many people, especially those who don't or can't take the time to understand the argument logic.
- Then he explains how economics data are not as easy to construct with universal agreement as with, say, physics (temperature). Agreement on practical action is hard when contrary frames and interpretations appear valid.
- He then mentions how this might be a problem for defining capital and other constructs for Piketty, but without any useful argument beyond this assertion.
- He then contrasts Feynman's integrity, trying to disprove his own work to make it better, to economist George Stigler's rhetorical style of conviction, ignoring contrary arguments, and playing the polemicist.
- He then mentions Isaiah Berlin's distinction between foxes who know little about something , and hedgehogs who know one big thing.
All these are interesting frames by which to compare and contrast various things. Yet his analysis, after bringing in all these ideas, is just to say that economics needs both careful analysis and effective rhetoric. Well, duh, but how does this tie into all the great setups he's made so far?
And mathy people are good at neither rhetoric nor polemic? But surely, if you're afraid of these people, they would be a mathy person who is using rhetoric to undermine the real philosophy and logic that should - pace Plato - be informing the argument.
It's a post full of story and setup, but as yet, signifying nothing.