Submission to observed or experimental data is the golden rule which dominates any scientific discipline. Any theory whatever, if it is not verified by empirical evidence, has no scientific value and should be rejected.
Formalistic deductive “Glasperlenspiel” can be very impressive and seductive. But in the realm of science it ought to be considered of little or no value to simply make claims about the model and lose sight of reality.
Mainstream — neoclassical — economics has since long given up on the real world and contents itself with proving things about thought up worlds. Empirical evidence only plays a minor role in economic theory, where models largely function as a substitute for empirical evidence. Hopefully humbled by the manifest failure of its theoretical pretences, the one-sided, almost religious, insistence on axiomatic-deductivist modeling as the only scientific activity worthy of pursuing in economics will give way to methodological pluralism based on ontological considerations rather than formalistic tractability.
To have valid evidence is not enough. What economics needs is sound evidence. Why? Simply because the premises of a valid argument do not have to be true, but a sound argument, on the other hand, is not only valid, but builds on premises that are true. Aiming only for validity, without soundness, is setting the economics aspirations level too low for developing a realist and relevant science.
We economists trudge relentlessly toward Asymptopia, where data are unlimited and estimates are consistent, where the laws of large numbers apply perfectly and where the full intricacies of the economy are completely revealed … Worst of all, when we feel pumped up with our progress, a tectonic shift can occur, like the Panic of 2008, making it seem as though our long journey has left us disappointingly close to the State of Complete Ignorance whence we began …
We may listen, but we don’t hear, when the Priests warn that the new direction is only for those with Faith, those with complete belief in the Assumptions of the Path. It often takes years down the Path, but sooner or later, someone articulates the concerns that gnaw away in each of us and asks if the Assumptions are valid …
It would be much healthier for all of us if we could accept our fate, recognize that perfect knowledge will be forever beyond our reach and find happiness with what we have …
Can we economists agree that it is extremely hard work to squeeze truths from our data sets and what we genuinely understand will remain uncomfortably limited? We need words in our methodological vocabulary to express the limits … Those who think otherwise should be required to wear a scarlet-letter O around their necks, for “overconfidence.”
Econometric theory promises more than it can deliver, because it requires a complete commitment to assumptions that are actually only half-heartedly maintained …
Our understanding of causal effects in macroeconomics is virtually nil, and will remain so. Don’t we know that? … The economists who coined the DSGE acronym combined in three terms the things economists least understand: “dynamic,” standing for forward-looking decision making; “stochastic,” standing for decisions under uncertainty and ambiguity; and “general equilibrium,” standing for the social process that coordinates and in uences the actions of all the players. I have tried to make this point in the title of my recent book Macroeconomic Patterns and Stories. That’s what we do. We seek patterns and tell stories.
As yours truly wrote last week, there has been much discussion going on in the economics academia on Paul Romer’s recent critique of ‘modern’ macroeconomics.
But the rhetorical swindle that New Classical and ‘New Keynesian’ macroeconomics have tried to impose upon us with their microfounded calibrations and DSGE models, has not gone unnoticed until Paul Romer came along:
I think that Professors Lucas and Sargent really seem to be serious in what they say, and in turn they have a proposal for constructive research that I find hard to talk about sympathetically. They call it equilibrium business cycle theory, and they say very firmly that it is based on two terribly important postulates — optimizing behavior and perpetual market clearing. When you read closely, they seem to regard the postulate of optimizing behavior as self-evident and the postulate of market-clearing behavior as essentially meaningless. I think they are too optimistic, since the one that they think is self-evident I regard as meaningless and the one that they think is meaningless, I regard as false. The assumption that everyone optimizes implies only weak and uninteresting consistency conditions on their behavior. Anything useful has to come from knowing what they optimize, and what constraints they perceive. Lucas and Sargent’s casual assumptions have no special claim to attention …
It is plain as the nose on my face that the labor market and many markets for produced goods do not clear in any meaningful sense. Professors Lucas and Sargent say after all there is no evidence that labor markets do not clear, just the unemployment survey. That seems to me to be evidence. Suppose an unemployed worker says to you “Yes, I would be glad to take a job like the one I have already proved I can do because I had it six months ago or three or four months ago. And I will be glad to work at exactly the same wage that is being paid to those exactly like myself who used to be working at that job and happen to be lucky enough still to be working at it.” Then I’m inclined to label that a case of excess supply of labor and I’m not inclined to make up an elaborate story of search or misinformation or anything of the sort. By the way I find the misinformation story another gross implausibility. I would like to see direct evidence that the unemployed are more misinformed than the employed, as I presume would have to be the case if everybody is on his or her supply curve of employment … Now you could ask, why do not prices and wages erode and crumble under those circumstances? Why doesn’t the unemployed worker who told me “Yes, I would like to work, at the going wage, at the old job that my brother-in-law or my brother-in-law’s brother-in-law is still holding”, why doesn’t that person offer to work at that job for less? Indeed why doesn’t the employer try to encourage wage reduction? That doesn’t happen either … Those are questions that I think an adult person might spend a lifetime studying. They are important and serious questions, but the notion that the excess supply is not there strikes me as utterly implausible.
The eminently quotable Solow — as always — says it all.
The purported strength of New Classical and ‘New Keynesian’ macroeconomics is that they have firm anchorage in preference-based microeconomics, and especially the decisions taken by inter-temporal utility maximizing ‘forward-loooking’ individuals.
To some of us, however, this has come at too high a price. The almost quasi-religious insistence that macroeconomics has to have microfoundations — without ever presenting neither ontological nor epistemological justifications for this claim — has put a blind eye to the weakness of the whole enterprise of trying to depict a complex economy based on an all-embracing representative actor equipped with superhuman knowledge, forecasting abilities and forward-looking rational expectations.
That anyone should take that kind of ludicrous stuff seriously is totally and unbelievably ridiculous. Or as Solow has it:
Suppose someone sits down where you are sitting right now and announces to me that he is Napoleon Bonaparte. The last thing I want to do with him is to get involved in a technical discussion of cavalry tactics at the battle of Austerlitz. If I do that, I’m getting tacitly drawn into the game that he is Napoleon. Now, Bob Lucas and Tom Sargent like nothing better than to get drawn into technical discussions, because then you have tacitly gone along with their fundamental assumptions; your attention is attracted away from the basic weakness of the whole story. Since I find that fundamental framework ludicrous, I respond by treating it as ludicrous – that is, by laughing at it – so as not to fall into the trap of taking it seriously and passing on to matters of technique.
Several mainstream economists still believe that ‘any interesting model must be a dynamic stochastic general equilibrium model. From this perspective, there is no other game in town. If you have an interesting and coherent story to tell, you can tell it in a DSGE model. If you cannot, your story is incoherent’ (V.V. Chair). Similarly, not very long ago, Blanchard (2014, p. 31) was affirming that the solution to previous mistakes was that ‘DSGE models should be expanded to better recognize the role of the financial system.’ It is hard to see how conceiving of the financial system as frictions to the real economy can help in understanding macroeconomics. Simon Wren-Lewis (2016, p. 33) is adamant that the methodology proposed by what he calls the New Classical Counter Revolution, enclosed into DSGE and New Keynesian models, is a worthy one, and that as a consequence ‘the microfoundations methodology is entrenched … so it is unlikely that its practitioners will down tools and start afresh’. Wren-Lewis further claims says that ‘the methodology is progressive’, and like Blanchard he believes that ‘researchers are devoting a good deal of time to examining real/financial interactions’ (2016, p. 30), so that all is well as long as Keynesian results are not excluded by assumption and can be recovered from the simulations.
There are many kinds of useless economics held in high regard within mainstream economics establishment today . Few — as Paul Romer recently has been arguing — are less deserved than the post-real macroeconomic theory – mostly connected with Nobel laureates Finn Kydland, Robert Lucas, Edward Prescott and Thomas Sargent – called calibration.
In an interview by Seppo Honkapohja and Lee Evans (Macroeconomic Dynamics 2005, vol. 9) Thomas Sargent says:
Calibration is less optimistic about what your theory can accomplish because you would only use it if you din’t fully trust your entire model, meaning that you think your model is partly misspecified or incompetely specified, or if you trusted someone else’s model and data set more than your own. My recollection is that Bob Lucas and Ed Prescott were initially very enthusiastic about rational expetations econometrics. After all, it simply involved imposing on ourselves the same high standards we had criticized the Keynesians for failing to live up to. But after about five years of doing likelihood ratio tests on rational expectations models, I recall Bob Lucas and Ed Prescott both telling me that those tests were rejecting too many good models. The idea of calibration is to ignore some of the probabilistic implications of your model but to retain others. Somehow, calibration was intended as a balanced response to professing that your model, although not correct, is still worthy as a vehicle for quantitative policy analysis….
It is — sad to say — a fact that within mainstream economics internal validity is everything and external validity and truth nothing. Why anyone should be interested in that kind of theories and models — as long as mainstream economists do not come up with any export licenses for their theories and models to the real world in which we live — is beyond comprehension. Stupid models are of no or little help in understanding the real world.
In Chicago economics one is cultivating the view that scientific theories has nothing to do with truth. Constructing theories and building models is not even considered an activity wth the intent of approximating truth. For Chicago economists like Lucas and Sargent it is only an endeavour to organize their thoughts in a ‘useful’ manner.
What a handy view of science!
What Sargent and other defenders of scientific storytelling ‘forgets’ is that potential explanatory power achieved in thought experimental models is not enough for attaining real explanations. Model explanations are at best conjectures, and whether they do or do not explain things in the real world is something we have to test. To just believe that you understand or explain things better with thought experiments is not enough. Without a warranted export certificate to the real world, model explanations are pretty worthless. Proving things in models is not enough. Truth is an important concept in real science.
If I am right that in recent decades the equilibrium in post-real macro has discouraged good science … there is some risk that a rear-guard of post-real macroeconomists will continue to defend their notion of methodological purity. At this point it is hard to know whether this group will fracture or dig in for a fight to death. If they dig in, I suspect that it will be in a few departments and that the variation between departments will be larger. Watch to see how this plays out and choose where you go with this in mind.
To learn about a department, visit and ask macroeconomists you meet “honestly, what do you think was the cause of the recessions of 1980 and 1982.” If they say anything other than “Paul Volcker caused them to bring inflation down,” treat this as at least a yellow caution flag. Then ask about cause of the Great Depression. If they start telling you about the anti-market policies of the New Deal, listen politely and scratch this department off your list.
James Tobin explained why real business cycle theory and microfounded DSGE models are such a total waste of time. Thirty years before Paul Romer. Maybe one should start teaching some history of economic thought at economics departments again? Just a thought …
They try to explain business cycles solely as problems of information, such as asymmetries and imperfections in the information agents have. Those assumptions are just as arbitrary as the institutional rigidities and inertia they find objectionable in other theories of business fluctuations … I try to point out how incapable the new equilibrium business cycles models are of explaining the most obvious observed facts of cyclical fluctuations … I don’t think that models so far from realistic description should be taken seriously as a guide to policy … I don’t think that there is a way to write down any model which at one hand respects the possible diversity of agents in taste, circumstances, and so on, and at the other hand also grounds behavior rigorously in utility maximization and which has any substantive content to it.
Arjo Klamer, The New Classical Mcroeconomics: Conversations with the New Classical Economists and their Opponents,Wheatsheaf Books, 1984
– The models are rubbish.
– Don’t be silly. There’s a paper from the 1980s on learning effects.
Commenting on the state of standard modern macroeconomics, Willem Buiter argues that neither New Classical nor New Keynesian microfounded DSGE macro models have helped us foresee, understand or craft solutions to the problems of today’s economies:
The Monetary Policy Committee of the Bank of England I was privileged to be a ‘founder’ external member of during the years 1997-2000 contained, like its successor vintages of external and executive members, quite a strong representation of academic economists and other professional economists with serious technical training and backgrounds. This turned out to be a severe handicap when the central bank had to switch gears and change from being an inflation-targeting central bank under conditions of orderly financial markets to a financial stability-oriented central bank under conditions of widespread market illiquidity and funding illiquidity. Indeed, the typical graduate macroeconomics and monetary economics training received at Anglo-American universities during the past 30 years or so, may have set back by decades serious investigations of aggregate economic behaviour and economic policy-relevant understanding. It was a privately and socially costly waste of time and other resources.
Most mainstream macroeconomic theoretical innovations since the 1970s … have turned out to be self-referential, inward-looking distractions at best. Research tended to be motivated by the internal logic, intellectual sunk capital and aesthetic puzzles of established research programmes rather than by a powerful desire to understand how the economy works …
Both the New Classical and New Keynesian complete markets macroeconomic theories not only did not allow questions about insolvency and illiquidity to be answered. They did not allow such questions to be asked …
Charles Goodhart, who was fortunate enough not to encounter complete markets macroeconomics and monetary economics during his impressionable, formative years, but only after he had acquired some intellectual immunity, once said of the Dynamic Stochastic General Equilibrium approach which for a while was the staple of central banks’ internal modelling: “It excludes everything I am interested in”. He was right. It excludes everything relevant to the pursuit of financial stability.
The Bank of England in 2007 faced the onset of the credit crunch with too much Robert Lucas, Michael Woodford and Robert Merton in its intellectual cupboard. A drastic but chaotic re-education took place and is continuing.
I believe that the Bank has by now shed the conventional wisdom of the typical macroeconomics training of the past few decades. In its place is an intellectual potpourri of factoids, partial theories, empirical regularities without firm theoretical foundations, hunches, intuitions and half-developed insights. It is not much, but knowing that you know nothing is the beginning of wisdom.
Reading Buiter’s article is certainly a very worrying confirmation of what Paul Romer wrote last week. Modern macroeconomics is becoming more and more a total waste of time.
But why are all these macro guys wasting their time and efforts on these models? Besides simply having the usual aspirations of being published, I think maybe Frank Hahn gave the truest answer back in 2005, when interviewed on the occasion of his 80th birthday, he confessed that some economic assumptions didn’t really say anything about “what happens in the world,” but still had to be considered very good “because it allows us to get on this job.”
Hahn’s suggestion reminds me of an episode, twenty years ago, when Phil Mirowski was invited to give a speech on themes from his book More Heat than Light at my economics department in Lund, Sweden. All the mainstream neoclassical professors were there. Their theories were totally mangled and no one — absolutely no one — had anything to say even remotely reminiscent of a defense. Being at a nonplus, one of them, in total desperation, finally asked “But what shall we do then?”
Yes indeed — what shall they do when their emperor has turned out to be naked?