LARS P. SYLL

Some unsettled questions in macroeconomic theory

What is mainstream economics?

The reason you study an issue at all is usually that you care about it, that there’s something you want to achieve or see happen. Motivation is always there; the trick is to do all you can to avoid motivated reasoning that validates what you want to hear.

In my experience, modeling is a helpful tool (among others) in avoiding that trap, in being self-aware when you’re starting to let your desired conclusions dictate your analysis. Why? Because when you try to write down a model, it often seems to lead some place you weren’t expecting or wanting to go. And if you catch yourself fiddling with the model to get something else out of it, that should set off a little alarm in your brain.

Paul Krugman 

Hmm …

So when Krugman and other ‘modern’ mainstream economists use their models — standardly assuming rational expectations, Walrasian market clearing, unique equilibria, time invariance, linear separability and homogeneity of both inputs/outputs and technology, infinitely lived intertemporally optimizing representative agents with homothetic and identical preferences, etc. — and standardly ignoring complexity, diversity, uncertainty, coordination problems, non-market clearing prices, real aggregation problems, emergence, expectations formation, etc. — we are supposed to believe that this somehow helps them ‘to avoid motivated reasoning that validates what you want to hear.’

Yours truly  is, to say the least, far from convinced. The alarm that sets off in my brain is that this, rather than being helpful for understanding real world economic issues, sounds more like an ill-advised plaidoyer for voluntarily taking on a methodological straight-jacket of unsubstantiated and known to be false assumptions.

Modern (expected) utility theory is a good example of this. Leaving the specification of preferences without almost any restrictions whatsoever, every imaginable evidence is safely made compatible with the all-embracing ‘theory’ — and a theory without informational content never risks being empirically tested and found falsified. Used in mainstream economics ‘thought experimental’ activities, it may of course be very ‘handy’, but totally void of any empirical value.

Utility theory has like so many other economic theories morphed into an empty theory of everything. And a theory of everything explains nothing — just as Gary Becker’s ‘economics of everything’ it only makes nonsense out of economic science.

Using false assumptions, mainstream modelers can derive whatever conclusions they want. Wanting to show that ‘all economists consider austerity to be the right policy,’ just e.g. assume ‘all economists are from Chicago’ and ‘all economists from Chicago consider austerity to be the right policy.’  The conclusions follows by deduction — but is of course factually totally wrong. Models and theories building on that kind of reasoning is nothing but a pointless waste of time.

Mainstream economics today is mainly an approach in which you think the goal is to be able to write down a set of empirically untested assumptions and then deductively infer conclusions from them. When applying this deductivist thinking to economics, economists usually set up ‘as if’ models based on a set of tight axiomatic assumptions from which consistent and precise inferences are made. The beauty of this procedure is of course that if the axiomatic premises are true, the conclusions necessarily follow. The snag is that if the models are to be relevant, we also have to argue that their precision and rigour still holds when they are applied to real-world situations. They often don’t do for the simple reason that empty theoretical exercises of this kind do not tell us anything about the world. When addressing real economies, the idealizations necessary for the deductivist machinery to work, simply don’t hold.

So how should we evaluate the search for ever greater precision and the concomitant arsenal of mathematical and formalist models? To a large extent, the answer hinges on what we want our models to perform and how we basically understand the world.

The world as we know it, has limited scope for certainty and perfect knowledge. Its intrinsic and almost unlimited complexity and the interrelatedness of its parts prevent the possibility of treating it as constituted by atoms with discretely distinct, separable and stable causal relations. Our knowledge accordingly has to be of a rather fallible kind. To search for deductive precision and rigour in such a world is self-defeating. The only way to defend such an endeavour is to restrict oneself to prove things in closed model-worlds. Why we should care about these and not ask questions of relevance is hard to see.

Economics — the triumph of ideology over science

Research shows not only that individuals sometimes act differently than standard economic theories predict, but that they do so regularly, systematically, and in ways that can be understood and interpreted through alternative hypotheses, competing with those utilised by orthodox economists.

To most market participants – and, indeed, ordinary observers – this does not seem like big news … In fact, this irrationality is no news to the economics profession either. John Maynard Keynes long ago described the stock market as based not on rational individuals struggling to uncover market fundamentals, but as a beauty contest in which the winner is the one who guesses best what the judges will say …

Adam Smith’s invisible hand – the idea that free markets lead to efficiency as if guided by unseen forces – is invisible, at least in part, because it is not there …

For more than 20 years, economists were enthralled by so-called “rational expectations” models which assumed that all participants have the same (if not perfect) information and act perfectly rationally, that markets are perfectly efficient, that unemployment never exists (except when caused by greedy unions or government minimum wages), and where there is never any credit rationing.

That such models prevailed, especially in America’s graduate schools, despite evidence to the contrary, bears testimony to a triumph of ideology over science. Unfortunately, students of these graduate programmes now act as policymakers in many countries, and are trying to implement programmes based on the ideas that have come to be called market fundamentalism … Good science recognises its limitations, but the prophets of rational expectations have usually shown no such modesty.

Joseph Stiglitz

Economics — non-ideological and valuefree? I’ll be dipped!

I’ve subsequently stayed away from the minimum wage literature for a number of reasons. First, it cost me a lot of friends. People that I had known for many years, for instance, some of the ones I met at my first job at the University of Chicago, became very angry or disappointed. They thought that in publishing our work we were being traitors to the cause of economics as a whole.

David Card

Back in 1992, New Jersey raised the minimum wage by 18 per cent while its neighbour state, Pennsylvania, left its minimum wage unchanged. Unemployment in New Jersey should — according to mainstream economics textbooks — have increased relative to Pennsylvania. However, when economists David Card and Alan Krueger gathered information on fast food restaurants in the two states, it turned out that unemployment had actually decreased in New Jersey relative to that in Pennsylvania. Counter to mainstream demand theory we had an anomalous case of a backward-sloping supply curve.

Lo and behold!

But of course — when facts and theory don’t agree, it’s the facts that have to be wrong …

The inverse relationship between quantity demanded and price is the core proposition in economic science, which embodies the pre-supposition that human choice behavior is sufficiently rational to allow predictions to be made. Just as no physicist would claim that “water runs uphill,” no self-respecting economist would claim that increases in the minimum wage increase employment. Such a claim, if seriously advanced, becomes equivalent to a denial that there is even minimal scientific content in economics, and that, in consequence, economists can do nothing but write as advocates for ideological interests. Fortunately, only a handful of economists are willing to throw over the teaching of two centuries; we have not yet become a bevy of camp-following whores.

James M. Buchanan in Wall Street Journal (April 25, 1996)

Economics — non-ideological and valuefree? I’ll be dipped!

What is truth in economics?

In my view, scientific theories are not to be considered ‘true’ or ‘false.’ In constructing such a theory, we are not trying to get at the truth, or even to approximate to it: rather, we are trying to organize our thoughts and observations in a useful manner.

Robert Aumann

What a handy view of science.

How reassuring for all of you who have always thought that believing in the tooth fairy make you understand what happens to kids’ teeth. Now a ‘Nobel prize’ winning economist tells you that if there are such things as tooth fairies or not doesn’t really matter. Scientific theories are not about what is true or false, but whether ‘they enable us to organize and understand our observations’!

What Aumann 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 ought to be as important a concept in economics as it is in real science.

What it takes to make economics a real science

What is science? One brief definition runs: “A systematic knowledge of the physical or material world.” Most definitions emphasize the two elements in this definition: (1) “systematic knowledge” about (2) the real world. Without pushing this definitional question to its metaphysical limits, I merely want to suggest that if economics is to be a science, it must not only develop analytical tools but must also apply them to a world that is now observable or that can be made observable through improved methods of observation and measurement. Or in the words of the Hungarian mathematical economist Janos Kornai, “In the real sciences, the criterion is not whether the proposition is logically true and tautologically deducible from earlier assumptions. The criterion of ‘truth’ is, whether or not the proposition corresponds to reality” …

One of our most distinguished historians of economic thought, George Stigler, has stated that: “The dominant influence upon the working range of economic theorists is the set of internal values and pressures of the discipline. The subjects of study are posed by the unfolding course of scientific developments.” He goes on to add: “This is not to say that the environment is without influence …” But, he continues, “whether a fact or development is significant depends primarily on its relevance to current economic theory.” What a curious relating of rigor to relevance! Whether the real world matters depends presumably on “its relevance to current economic theory.” Many if not most of today’s economic theorists seem to agree with this ordering of priorities …

Today, rigor competes with relevance in macroeconomic and monetary theory, and in some lines of development macro and monetary theorists, like many of their colleagues in micro theory, seem to consider relevance to be more or less irrelevant … The theoretical analysis in much of this literature rests on assumptions that also fly in the face of the facts … Another related recent development in which theory proceeds with impeccable logic from unrealistic assumptions to conclusions that contradict the historical record, is the recent work on rational expectations …

I have scolded economists for what I think are the sins that too many of them commit, and I have tried to point the way to at least partial redemption. This road to salvation will not be an easy one for those who have been seduced by the siren of mathematical elegance or those who all too often seek to test unrealistic models without much regard for the quality or relevance of the data they feed into their equations. But let us all continue to worship at the altar of science. I ask only that our credo be: “relevance with as much rigor as possible,” and not “rigor regardless of relevance.” And let us not be afraid to ask — and to try to answer the really big questions.

Robert A. Gordon

Mainstream economists dissing people that want to rethink economics

There’s a lot of commenting on the blog now, after yours truly put up a post where Cambridge economist Pontus Rendahl in an interview compared heterodox economics to ‘creationism’ and ‘alternative medicine,’ and totally dissed students that want to see the economics curriculum moving in a more pluralist direction.

Sad to say, Rendahl is not the only mainstream economist having monumental problems when trying to argue with people challenging the ruling orthodoxy.

A couple of years ago Paul Krugman felt a similar urge to defend mainstream neoclassical economics against the critique from students asking for more relevance, realism and pluralism in the teaching of economics. According to Krugman, the students and people like yours truly are wrong in blaming mainstream economics for not being relevant and not being able to foresee crises. To Krugman there is nothing wrong with ‘standard theory’ and ‘economics textbooks.’ If only policy makers and economists stick to ‘standard economic analysis’ everything would be just fine.

I’ll be dipped! If there’s anything the last couple of years have shown us, it is that economists have gone astray. Krugman’s ‘standard theory’ — mainstream neoclassical economics – has contributed to causing todays’s economic crisis rather than to solving it. Reading Krugman, I guess a lot of the young economics students that today are looking for alternatives to mainstream neoclassical theory are deeply disappointed. Rightly so. But — although Krugman, especially on his blog, certainly tries to present himself as a kind of radical and anti-establishment economics guy — when it really counts, he shows what he is —  a die-hard teflon-coated mainstream neoclassical economist.

Perhaps this becomes less perplexing to grasp when one considers what Krugman said in a speech (emphasis added) in 1996:

I like to think that I am more open-minded about alternative approaches to economics than most, but I am basically a maximization-and-equilibrium kind of guy. Indeed, I am quite fanatical about defending the relevance of standard economic models in many situations …

Personally, I consider myself a proud neoclassicist. By this I clearly don’t mean that I believe in perfect competition all the way. What I mean is that I prefer, when I can, to make sense of the world using models in which individuals maximize and the interaction of these individuals can be summarized by some concept of equilibrium … I have seen the propensity of those who try to do economics without those organizing devices to produce sheer nonsense when they imagine they are freeing themselves from some confining orthodoxy.

So now all young economics students that want to see a real change in economics and the way it’s taught — now you know where you have people like Rendahl and Krugman. If you really want something other than the same old mainstream neoclassical catechism, if you really don’t want to be force-fed with mainstream neoclassical theories and models, you have to look elsewhere. 

On the proper use of mathematics in economics

One must, of course, beware of expecting from this method more than it can give. Out of the crucible of calculation comes not an atom more truth than was put in. The assumptions being hypothetical, the results obviously cannot claim more than a vey limited validity. The mathematical expression ought to facilitate the argument, clarify the results, and so guard against possible faults of reasoning — that is all.

It is, by the way, evident that the economic aspects must be the determining ones everywhere: economic truth must never be sacrificed to the desire for mathematical elegance.