Milton Friedman's Thermostat
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Friedman just said that the Fed acts like a thermostat, and in the linked paper, claimed that the period subsequent to 1985 had increased price stability owing to improvements in their understanding of inflation and it's relation to the quantity of money, hence their "better thermostat".
AFAICT, the OP has made up this "Friedman's Thermostat" insofar as it relates to economic forecasting, and now he wants to know why no one has heard of it.
As an aside, "exception that proves the rule" is an almost universally misapplied phrase, that should only be used if you're really really sure you know what it means (kind of like "begs the question").
[1] http://online.wsj.com/article/0,,SB106125694925954100,00.htm...
[2] OP = Nick Rowe - http://worthwhile.typepad.com/worthwhile_canadian_initi/abou...
And I'm also confused by what you mean by "the OP has made up this 'Friedman's Thermostat'"... seriously, what does that mean? Friedman wrote a paper on Friedman's Thermostat. So how could OP [whoever that is, I assume you mean Nick Rowe] have "made it up"?
But the article is not claiming that there is a "general thermostat theory." He's talking about one idea (there may be no measured correlation under targeting) and asking why this is not more widely known, especially since the abstract idea seems more widely applicable (to fields other than monetary theory and applied econometrics).
The inverse of Rowe's claim is that this idea is well known (maybe under a different name). Are you arguing that? If so, then by what name?
No he didn't.
He just used the WORD "thermostat" once, in an article.
And his use of the word was unrelated to the concept presented in the blog post (which is not Friedman's but older and which nobody calls "Friedman's thermostat" except the author of the blog post).
Here's an analogy for the situation:
David Pogue writes and article titled "The perfect gadget for Christmas", which is simply a review of 10 hot current gadgets.
Then, 30 years later, some blogger writes "How come nobody knows "Pogue's Perfect Gadget" theory? You know the one that says that when you put a cat inside a gadget's enclosure with a quantum based poisoning device the cat's state is both dead and alive?"
He then goes to admit that idea: is not Pogues, it was found earlier, and nobody calls it that -- all the while complaining why people don't know it by his made up name "whereas they do some other Pogue's articles".
The whole blog post smells crank to me...
Nick Rowe is abstracting away some of the specifics of Friedman's article, but he's talking about the same concept : how active targeting of one measure can achieve desirable changes in another one while still showing no/little correlation between the two.
Rowe is also applying that abstraction to another concrete example: the pedals in a car driving in a hilly area.
Nick Rowe: "Google seems to tell me I'm right. I'm the first link, which is really pathetic for such an important idea."
Not to mention that googling for "Fed Thermostat" brings up a lot of references. Friedman's is in the top page, Nick's is not:
So I don't think he's criticizing people for not knowing the specific name, but there's some egotism at play. He likes the idea he identified and the name he came up with, and is scratching his head that only market monetarists have picked up the name and that his blog--minor in the blogosphere--is still the first link.
Full quote:
Google seems to tell me I'm right. I'm the first link, which is really pathetic for such an important idea; the second is Friedman himself (pdf); and most of the rest on the first page are other bloggers, mostly Market Monetarists. But this idea has got nothing (in particular) to do with Monetarism.
But arguing about the interpretation of this sentence ultimately is a red herring--you don't go into rage-mode about a blog post because most of it says X but one sentence seems to say Y instead, especially if you can't be sure it even says Y.
He does not appear to be an Econometrician, nor a Statistician (I can't find his CV, which is odd), so the most likely answer is that he is wrong, and that this is a well understood phenomenon for which he doesn't know the proper technical term (viz., Multicollinearity).
This quote from his blog post sums it up for me (emphasis mine):
"And it really bugs me that people who know a lot more econometrics than I do think that you can get around the problem this way, when you can't"
[edit] - @cynicalkane - we are in violent agreement on the core theory, but equally violent disagreement on the extent to which his link-baity title & appropriation of Friedman's name is academically disingenuous.
Shall we call it a day?
I'm also not sure why you keep blasting him for not using the word "multicollinearity", when he's talking about a fairly specific kind of hidden variable anyway, and one that you simply can't pluck out of small macro data sets ex nihilo especially in the face of the Lucas critique.
For instance, in this blog post, http://ipeatunc.blogspot.com/2012/08/its-not-just-data-its-a... , a blogger discusses Milton Friedman's thermostat and then, in the comments, discusses deliberately leaving technical terms such as multicollinearity out of the post.
First paragraph of blog article.
I'm tremendously skeptical of economics-based policy papers. A biologist works on a paper for years, and concludes that this kind of gene expression might be linked to this kind of nutrient deficiency. An economist at a "think tank" works on a paper for a fraction of that time and gives advice on how to structure a tens of billions of $ industry...
Re: think tanks, isn't it something that even in supposedly less rigorous fields like, oh English literature, such upfront results-orientation would be considered the badge of unserious scholarship?
Nowhere near as fishy as how think tanks work, but how scientists and academics think about hypotheses is actually very complex and you'd be surprised at how often unserious scholarship is tolerated.
E.g. it's not uncommon to first write a paper and then tag on a hypothesis that just happens to agree with your conclusion, to change the hypothesis when your own research proves it to be wrong (it's hard to get research published about things that didn't work), or to try everything you can to prove a hypothesis, rather than to try and falsify it.
And it's important to note that "appropriate skepticism" != "ignore everything they say". Just because a person is an advocate of a position doesn't mean their facts are wrong or their arguments are incorrect.
And yes, I generally ignore what people at think tanks say. Life is too short, and I prioritize the views of people whose credibility isn't compromised from step 1.
The things we talk about today are not really that diffrent from what Adam Smith argued for/against a couple hundert years ago. Today you have people like Stigliz arguing against markets with much more sophisticated models then the people that argued against Adam Smith. The people that argue against Stigliz use much better models too. So where does that leave us?
I conclude that we should let the market be the market and not try to influence it, its a far more complex thing then economist understand. Trying to influence in to one direction will probebly just cause ten more things that are unexpected. The market is not perfect, not even close, read Stigliz as a good example of this but I highly doute that the goverment can improve the end result in most cases. If you look at the pridictions of TOP economist at every time X, the are almost always wrong and you get some other people that get it right, these people are then wrong the next time.
I barly trust the goverment to do the easy things write, tweek a huge economy is far from easy.
Also, the knee-jerk cynicism about the effectiveness of government is misplaced. E.g. government funds about 1/3 of all R&D in this country (and it was as high as 2/3 in 1964). It is definitely not the least productive third of the R&D expenditures. We crow about all these advances in medical technology, etc, but many of those advances are the direct result of enormous NIH funding. Our world-leading universities get well over half their R&D funding from the government.
I disagree: The economic argument against price controls is a very good one, and it's completely valid and useful to raise against the idea when governments try to use them to "solve real problems".
Seams to me the goverment does what it does and if the can find economist that agree with them then they are just happe they can clame that 'economist' agree with what there doing. They are not actually listening to them.
I have more of a problem with direct muddling like saving firm A or B, implementing ristrictions on trade, telling people what they can buy and what they cant buy. These things do not have to be discarded because of econmic reasing, these things have to be discard since the are plainly just goverment helping some people on the cost of others or just restring what people would want to do and are rational enougth to do.
I have some things I want to add to what you said. First and most importend is that you dont know what would have been devloped if people where taxed X% less instead of the goverment investing it. Second I think meassure what R&D is in a economy is very hard to say. Many thing just get evolutionarly better and that does not have to happen in R&D.
Third I would say that goverment funding universitys and things like that is something diffrent from a goverment burocracy. The universitys have other insentive to prudce good results, so do the comanys competing for grants. So I do think that goverment spending on reasearch is one of the best things goverments does.
Most of the size and scope of at least the federal government is things like this, not bureaucracy. The federal civilian payroll has held steady at 1.8-2.2 million since 1960, and payroll expenses account for less than 5% of the budget.
Defending a country is a hugely complicated mess, and moving battleships over here is going to have ramifications over there. Policing society is difficult and complicated - we try to cut down on crime by targeting something over here, and it causes problems over there.
Clearly, we should call the whole thing off, and allow international affairs and society take care of themselves - all the way through invasions and murder?
Evolution doesn't need biologists, but people who need to make decisions dealing with the consequences of evolution on epidemiology sure do!
Well you uncoverd the reason to why I belive, what I belive.
> Evolution doesn't need biologists, but people who need to make decisions dealing with the consequences of evolution on epidemiology sure do!
I agree but the question is not if we plan and make dicisions, the question is who makes the plan and dicisions for who.
> Defending a country is a hugely complicated mess, and moving battleships over here is going to have ramifications over there. Policing society is difficult and complicated - we try to cut down on crime by targeting something over here, and it causes problems over there. > Clearly, we should call the whole thing off, and allow international affairs and society take care of themselves - all the way through invasions and murder?
Well I actually agree that we should let society take care of that (Not trolling I actually agree).
The most broken down version of such a, for a advanced economy would be this (20 min video): How to provide law and police without state: https://www.youtube.com/watch?v=jTYkdEU_B4o
And a more practical discussion about order without goverment you can get here (lecture): https://www.youtube.com/watch?v=_pNrtgioFs0
Stats of Anarchy (or self goverments) or something close to it is one of the hot subjects in development economics. About half of the world stats are failed or almost failed states, these are states that do not have the power to efficently do what a policy and law system would do in a first world country. So there most be something else going on, why do the work as well as they do and people are not killing each other all the time.
This paper was quite influential: "Assume Anarchy? Why an Orthodox Economic Model May Not Be the Best Guide for Policy." Raghuram Rajan (Director of the IMF’s Research Department)
Im not saying that I can prove that the institutonal structure discribed in the videos above (and the reaseach of all the people) would work they way I would want it to but I do think it has potential to improve on democracy.
Anarchist and anarcho-capitalist ideas are fascinating but I'm still more than a bit skeptical.
I would point you to everything by David Friedman and Peter Lesson. I think they have done the best work in that area.
Edit: If you have questions, the reddit Anarcho Capitalist Subreddit is quite civil as far as reddit goes. So if you have questions you might want to ask there, r/anarcho_Capitalism.
> And no, you can not get around this problem by doing a multivariate regression of speed on gas pedal and hill. That's because gas pedal and hill will be perfectly colinear.
This is one of the reasons why you check for multicollinearity [1] when performing multivariate linear regressions; aside from introducing significant instability into the model, if your predictors are correlated, then you're essentially measuring the same thing twice. The stated problem is actually a good example as to why you should avoid having highly correlated predictors in a multivariate model; by blindly pursuing the regression despite the inputs being correlated, we miss out on the fact that there is a relationship present (i.e., the dependent variable (speed) is actually a factor of both of the independent variables (pedal height and hill slope)).
It always sucks when you accuse an entire profession of overlooking a fundamental principle, only to find out you've committed the same error in a more egregious fashion.
The criticism generalizes to any statistical methods, though. You always need to think about the underlying model before doing any kind of statistics in any science.
We are often surrounded by "armchair specialists" who know little about what they are talking about, yet carry large opinions about said topic. I'm all for constructive discourse, but that seems like a rare thing when talking about hot topics.
More commonly, you'll end up with imperfect multicollinearity, which means that two variables are almost the same, but slightly different. The danger with perfect multicollinearity is that (a) you'll end up with very high variances associated with those predictors, but furthermore (b) the predictor reported as being the 'strongest' may actually not be the strongest. In fact, it may not even be relevant; the model just "happens to be associating most of the variation in the response variable with that predictor. It's a more complicated version of this principle: http://xkcd.com/882/
I mention this because I see people - including people who should know better! - falling into this trap all the time. It's easy to overlook, particularly when you see the results you were expecting.
Now it is true that you can measure collinearity between the hillAngle and the pedalAngle and show that they are correlated... but we sorta knew this already, didn't we? After all, we're setting the pedalAngle based on the hillAngle. We created that functional relationship. There's no need to empirically discover it.
Put it another way. Suppose v = w1 * hillAngle + w2 * pedalAngle + v0, and you want to find w1 and w2.
If your dataset shows pedalAngle = -hillAngle, then you have
v = w1 * (-pedalAngle) + w2 * pedalAngle + v0 = (w2 - w1) * 0 + v0
So you're dataset tells you nothing about w1 and w2.
Everybody knows that if you press down on the gas pedal the car goes faster, other things equal, right? And everybody knows that if a car is going uphill the car goes slower, other things equal, right?
But suppose you were someone who didn't know those two things. And you were a passenger in a car watching the driver trying to keep a constant speed on a hilly road. You would see the gas pedal going up and down. You would see the car going downhill and uphill. But if the driver were skilled, and the car powerful enough, you would see the speed stay constant.
So, if you were simply looking at this particular "data generating process", you could easily conclude: "Look! The position of the gas pedal has no effect on the speed!"; and "Look! Whether the car is going uphill or downhill has no effect on the speed!"; and "All you guys who think that gas pedals and hills affect speed are wrong!"
Not to go off topic, but it's hard to take any "economist" talking head seriously these days. I'm currently re-reading The Road to Serfdom by F.A. Hayek (highly recommend) and it's scary to see that even 60 years ago we understood cycles and events that are still being ignored today.
The sad fact remains that real economic policy is no longer in vogue in Washington or the L.A. TV sets. What is popular these days is hand wavy gestures that seem to please the most amount of people... the science be damned.
Rather scary stuff.
For a more evidence-based approach, I'll go with Keynes' General Theory, which works, but has few adherents among the major parties in the West.
If we wanted to try and accurately describe the economic policy by the government in Washington, you'd have to describe the monetary and fiscal policies. Both of these since 2007 have been Keynesian far more than the other two schools (Monetarist and Austrian).
This hasn't always been the case (Friedman was much more in vogue from the late 70s to approximately late 90s as measured by policies put in place).
Keynes General Theory could theoretically work as he describes in his book, but is unrealistic in practice because of the political dynamics in government.
[1]http://krugman.blogs.nytimes.com/2009/10/05/the-story-of-the...
Im sorry this is not right. It is in fact dead wrong!
The austrian have from the VERY, VERY start objected to models that discribed market as perfect, or people as perfectly rational. Go into the internet and look up what austrians actually say about markets, google 'Market Process Theory'. It is actually the case that most of austrian theory trys to figure out how a groupe of ignorent humans like we are with our imperfection can creat such a complex structure of production or what Hayek called 'The extended order'
Why do people that have a bar half knowlage of economics, clame such wild things about a 120 year old tradition of economic thought.
The thing that most austrians clame, is that the market produces better results then a goverment influencing the market can that is because goverment does not have the knowlage (nor the insentive but that more public choice theory) to imporve the market outcome.
The problem is that with optimal we usally mean theoreticly optimal in such debates. In terms of practical solution we speak of comperative advantage (in comperative institutional analysis).
http://www.aei-ideas.org/2012/08/explaining-paul-ryans-austr...
Sure Bush talked about Free Markets but not even closly did anything about it, what he did was start a war, make a lot of debt, regulation increased in that time too.
Goverment only ever gets bigger, with very few expetion. From a free market perspective the republicans are not any diffrent then the democrats.
I btw am not from america, I have no idiolocial views in american politics, I just obeserve that both partys are not free market at all.
It was actually a democrat who was the only one that at least ran on a balanced buget (clinton).
Maybe you cannot describe those policies as Monetarist or Austrian. But given that everybody's policies there are driven by some desire to cut the budget deficit at a time of a very weak economy - with the only disagreement being over how the cuts should look - it just seems very bizarre to call that Keynesian.
First of all neither stimules nor saving companys is anything to do with free markets.
Both party want to spend more money, I would not belive for a second that republicans are more free market then democrats. The like to talk about it more but they infact are just ass bad. The real diffrence is what friends they have.
Both partys like to spend money on there friends.
Lets talk about free markets again when the actually DID cut the buged and I think nobody denys that the stimuls is keynesian.
What has to be considerd is that goverment actors are just as dumb ass market acters, with the importend diffrance that there own ass is not on the line.
I think the biggest error in 20 century economics has been to think that the general equillibrium model has any relevane to the real world.
We can agree on this part, and I'll further add that it's also a tremendous error to ignore that the equillibrium is dynamic and to ignore or downplay what happens in the intermediate periods during which the system is in disequillibrium.
To explain how the market reaches equillibrium (mostly only in theory) or how it at least sometimes moves towards equillibrium (mostly in the real world) is what economic analysis must provide. Just like Darwin explained what make evolution work.
The Theory behind this is called Market Process Theory, it is mostly created by people from the Austrian School of Economics but also from a lot of swedish economist.
But the real reason that nobody pays too much attention to Hayek is that the way countries recovered from the Great Depression worked entirely counter to Hayek's predictions. Going off the gold standard worked. It worked really well for every country that tried it! The way that the events of the 1970s conclusively disproved paleo-Keynesianism.
So now we have neo-Keyesianism as endorsed by people like Krugman and Monetarism from people like Friedman and they agree about a lot more stuff than Hayek and Keynes did. Now, they use different terms and have different ideas about the transmission mechanism by which monetary and fiscal policy influences aggregate demand, but everybody these days thinks of aggregate demand as the thing that drives fluctuations in the business cycle. That's progress, maybe in another 100 years economics will be a real science.
And please don't take the talking heads that show up on TV seriously. Mainstream reporting of economics is just as bad as it is of every other technical field.
I think you're rather over simplifying things. I'm no economist, but I make it my business to be at the least knowledgable about such things, and I feel recovery from the Great Depression was more of a combination of New Deal infrastructure, WWII profiteering and the resultant increase of wealth in US that was then transferred to Europe to aid in the rebuilding. But then again, that's probably one of the most complex economic time periods in modern history so I don't pretend to know everything.
To address the gold standard, there are indicators that removing the gold standard may have benefitted in the short term, but will hurt us in the long term.
I dont want to go into the hold Great Depression discussion, I just wanted to point out that hayek would have made the argument that the New Deal made the GD much longer, same with the WW2. The idea that a war can help the economy would made hayek cry.
Watch this modern Rap-Video of Hayek vs. Keynes and listen closly when the talk about the war.
I would reconsider your argument here. (1) Hayek was not a huge gold fan as it is, he changed his views on money changed over the years
(2) The gold standard that exist at the time is something very diffrent then that gold standard, gold advocates actually wanted
(3) The third and I think most importend one is that if you inflate on a gold standard, deflating back to that standard is like driving over somebody and then backing up over that person. The right solution would have been to stop prudction of money and see the new price of gold and then fix the doller to that standard again.
(4) Hayek is actually still very relevant and even mainstream. What we have to understand here it is perfectly possible to reject hayeks macro but not his micro, or the other way around. Hayek is infact very respected for his devlopment of information economics in particular.
> So now we have neo-Keyesianism as endorsed by people like Krugman and Monetarism from people like Friedman and they agree about a lot more stuff than Hayek and Keynes did.
Here you are assuming that austrians did not change since the the 50s.
Modern austrians macro in fact are really close to modern monetarist. There is infact wide agreement between Market Monetarist and Austrian Free Bankers. I would even clame that the are much closer together then neo-keynsians are.
I would also argue that mainstream economics now is much closer to austrian economics then it was 50 years ago. Things like Public Choice Theory, Law&Economics, New Institutional Econoimcs are all much closer to austrian economics then the are to standard neoclassical economimcs.
Austrians have been talking about the role of the entrepreneur for a long time, modern development economics only in the last decade started agree that it is importend, movment like micro finance are all things that spring from this.
Economists are largely unaware of what you describe as "basic economic theory" because you've defined "basic economic theory" in an unconventional way that's incompatible with how most economists describe economic theory.
There are a couple of econ departments that subscribe to "Austrian economics," and they view Hayek as basic economic theory. But they are viewed ideological hacks by the larger community.
A better example would be the proposed increase on capital gains/investment tax. Almost all economists, regardless of ideology, would agree that this will certainly be detrimental. And yet we continue to see "Professors" and "Analysts" explain how sticking it to the rich will solve everyones problems... through science!
Similarly, reducing government spending will have serious disadvantages/costs. We'd like not to cut government programs.
When economists advocate either of these, it isn't because they love higher taxes (or less spending on government programs). It is because we will need to close the gap between government revenue and expenditures. Doing so will require actions that we'd prefer we didn't have to take.
As an analogy, consider our collective decision that we'll all have a vote, and decide whether each of us has to cut off a finger or each of us has to cut off a toe. If we don't decide soon, we'll have to cut off two fingers (and two toes) later on.
Some of us would go on TV and declare "We want to cut off our toes." That's not because we'd prefer to have 4 toes. We're just voicing our preference given a choice we'd prefer we didn't have to make.
The same can be said of economists advocating for higher capital gains taxes.* They'd prefer low capital gains taxes if we didn't face hard choices. But we'll have to make choices we don't like in order to reduce the deficit.
* You could probably find pundits out there who hate wealthy people as a matter of ideology. I'm not including them when I talk about "economists," and those pundits are generally laughed at by the research economics community.
His book basically declares war on most other economists too: http://www.amazon.co.uk/Debunking-Economics-Revised-Expanded...
I'm very impressed but I'm always looking for counter arguments to my current understanding so if you know of any good critiques of his stuff I would be very interested.
Its pretty fascination stuff b/c MMT says that the mainstream has everything backwards.
http://moslereconomics.com http://neweconomicperspectives.org http://www.amazon.com/Currency-Economics-Modern-Monetary-ebo...
I don't recognise items (1), (2) or (3) or even (4) as such in his writing although I'm not sure they contradict it. (5) is very important and I think that he might say that (6) is the wrong way round and that the government is the agent of the banks at the moment!
His key issue is that debt (public and private) matters and that the rate of change in total debt is the main source of the booms and busts that we see.
His prescription for the current crisis is printing money but then to give it to the people not the banks or government (both of which we are doing now). People with debts would then be required to pay down the debts with the printed money and people without debts could keep and spend the printed money.
He also has some proposals for limitations on limitations on borrowing for property purchases (PILL) and one intended in preventing share speculation getting out of control too although I have my doubts about that one really as it seems impractical, abusable and has some potential negative effects too (Jubilee Shares). http://www.debtdeflation.com/blogs/manifesto/
On point 6) the government has statutory control of the banks. Its just that the banks have captured the government. War-hawk generals getting control of our foreign policy would be the analog.
edit: video of steve keen with MMT profs http://www.youtube.com/results?search_query=steve+keen+scott...
The real answer was that they were giving it the right amount of weight. If they were overweighting the GMAT, unqualified people with high GMATs would get in. If they were not underweighting it, the opposite.
Approximately 10 years later they did a correlation of student GMATs (which weren't used for admissions purposes) and school success, and found that there was indeed now a correlation.
The lesson was that if you're properly managing a factor, you won't see it in the outcome. Or in the thermostat example, if you're properly managing the thermostat, you won't see the changes.
We haven't heard of the thermostat because it does not introduce new ideas to us. If the data includes hill height, this is an example of multicollinearity. If your data does not include hill height, this is an example of endogeneity.
Both concepts are taught in considerable depth in an undergraduates first course in econometrics. It's a nice examples, but the author's claim that these phenomena are outside are awareness shows a striking ignorance of basic econometrics.
(I am not an economist and have no position on this; just curious.)
A 1983 study by Lars Peter Hansen of the University of Chicago and Kenneth Singleton of Stanford showed that short-term rates on Treasury bills and short-term returns on stocks traded on the New York Stock Exchange had very little correlation with consumer spending. Many empirical studies have confirmed this sort of result (this comparison of inflation-adjusted Treasury bill returns and business sector profitability is a recent example).
This summarizes "many empirical studies" in a single sentence. Unfortunately, it doesn't include citations.
There are a number of ways to address the "thermostat" problem. Each potential solution only works in specific circumstances. I'd hope the underlying research adequately addresses this concern, but it's hard to say without seeing the research.
In general, summarizing "many" 40 page papers in a paragraph is inherently difficult, and Mulligan seems to be especially vague here. If the claims here have any credibility, it would only be through an "appeal to authority," which most of us won't find very compelling.
So to answer your question, I'm unimpressed with the Mulligan column... in part because we have no indication what problems there are in the underlying analysis.
I'm no expert on statistics, but this seems like a pretty basic scenario for a statistical analysis to provide insight into. These two phenomena would be perfectly correlated in both the time of appearance and the degree.
You wouldn't be able to derive anything about the effect of hills or gas pedals on speed, but you'd be given a powerful clue as to what's going on.
The second there's even a tiny imbalance between the two, you're given the relationship to speed.
However, in a real world system, the chance that there is zero imbalance is also nearly infinitesimal. You could take the most skilled driver in the world and you would still be able to pull out the relationship between gas pedal and speed out of his driving pattern. Similarly, with the right variables and enough data, you could pull a relationship like the one described here out of economic data.
(As a side note, I think the way in which this article is written is pretty obnoxious. The first 500 words are dedicated to the author congratulating himself for being aware of an idea that he hasn't even explained yet.)
Both are scalars in that example, and the basic problem remains.
Another, more complex system: temperature of human body, temperature of air and perspiration.
I fall into this a lot, but I really hate the attitude of engineers and scientists believing that everything can be solved by approaching a problem a certain way. We have this idealized, fetishized approach that if you define all your axioms and have a rigid framework in place, you can solve anything. Of course, as soon as you try it in real life, especially in a field like sociology or economics (which, of course, we deride as not being scientific enough), it all goes to hell.
I would recommend that anyone who is of this opinion - that economics, psychology, linguistics, et al are not scientific enough - actually take a course in that area. What you find are: people who are experts in a field are really smart, yes, they have thought of that already, no, it didn't work. It's a very humbling experience.
Interesting. Can we come up with some general method of answering questions like "does institution X really play a part in keeping parameter Y stable?"
There's another way to find the relationship between the gas pedal, slope, and speed that the author did not mention (but is somewhat related to some of his suggestions): write down a model of the driver that assumes he or she uses the gas pedal to try to keep speed constant:
E_{t-1} speed(gas_t, slope_t, parameters) = const (eq1)
where E_{t-1} is the conditional expectation of the period-t term, given the information available in period t-1. Maybe speed should be nonparametric, but that will introduce some new problems in estimation; maybe you know enough about physics to write down a parametric formula for speed; whatever, the exact details of speed(.,.) are kind of beside the point for the author's argument.
Now,
speed(gas_t, slope_t, parameters) - E_{t-1} speed(gas_t, slope_t, parameters) (eq2)
is a martingale difference sequence when "parameters" is set to their true value, so the sequence equals zero in expectation for all t, assuming the model is true, and that can be the basis for estimation through, say, Generalized Method of Moments. Because combining (eq1) and (eq2) gives us
E speed(gas_t, slope_t, parameters) = const,
so you can estimate the parameters as
\hat parameters = argmin (average_over_t speed(gas_t, slope_t, parameters) - const)^2
Everything I laid out is an extreme simplification of the DOMINANT STRATEGY in applied macro (with, in all likelihood, some errors due to sloppiness). Now, for any realistic economy, it's going to be hard as hell to write down a sensible formula for "speed(.,.,.)" and since there aren't that many years since WWII (which is kind of seen as the beginning of the "modern" economy) there isn't a lot of data to estimate the model, but neither of those issues have anything to do with the author's "critique" and are basically the direction of almost all research in macro.
\hat parameters = argmin (average_over_t speed(gas_t, slope_t, parameters) - const)^2"
No you can't.
Think about it.
1. If the driver has as much information as the econometrician, setting both parameters on slope and gas equal to 0 will fit the data equally well.
2. If the econometrician observes slope and gas and speed with error (as will almost always be the case), then GMM will estimate both parameters on slope and gas as zero (if those 3 errors are independent of each other), even if the true parameters aren't.
3. If the driver observes gas or slope with error, and the econometrician doesn't, then the econometrician can indeed actually estimate the parameters.
How likely is 3? Only a stupidly arrogant econometrician would assume a priori that he knows better how to drive the car than the guy actually driving it. (OK, maybe the econometrician has final revised data, and the driver has only real time data, and the final revised data is better than the real time data. But even then the driver will be observing other indicators that the econometrician doesn't have data on, so the econometrician will interpret the driver's response to those omitted variables as "gas pedal shocks", and will screw up the estimation royally.
Yep, all that Sims VAR stuff is wrong. Here, read this.
http://worthwhile.typepad.com/worthwhile_canadian_initi/2011...
You have just proved my point: economists don't understand Milton Friedman's thermostat.
Forget your fancy stuff. Just STOP AND THINK about what you are really doing when you try to estimate parameters.
As I'm sure you know, these arguments (i.e. mainstream Economics is wrong and ignorant!) are more convincing when they're accompanied by a model. DSGE models have a lot of limitations, but they're pretty good for demonstrating failure of identification. Monetary policy is tricky to identify, and I'd be sympathetic to an argument showing that deviations from a Taylor-rule are bad for identifying the effects of monetary policy shocks (lots of people would agree with this, the interesting question is whether they're bad in empirically important ways or just conceptually bad) but your car+driver analogy seems like it's aiming to be broader than that.
This is just a particular beef I have. Because I keep on seeing examples where economists make mistakes by missing this point. Like when economists try to test whether headline or core inflation is better at forecasting future inflation, and use those results to give policy advice on whether inflation-targeting central banks should respond to core, headline, or both indicators. All they are modelling is the central bank's mistakes, in responding too strongly or too weakly to those indicators.
I think proper identification does require the econometrician be (in some sense) a "better" driver than the driver. If you can see the hills better than the driver can, then you can see the effects of a hidden hill that you know he doesn't see.
http://themonkeycage.org/blog/2012/07/31/milton-friedmans-th...
Um, what? For a constant speed, which is this person's example, this claim is completely false.