LARS P. SYLL

Mainstream economics — a pointless waste of time

Paul Krugman has a piece up on his blog arguing that the ‘discipline of modeling’ is a sine qua non for tackling politically and emotionally charged economic issues:

You might say that the way to go about research is to approach issues with a pure heart and mind: seek the truth, and derive any policy conclusions afterwards. But that, I suspect, is rarely how things work. After all, 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.

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.

Let me just give two examples to illustrate my point.

In 1817 David Ricardo presented — in Principles — a theory that was meant to explain why countries trade and, based on the concept of opportunity cost, how the pattern of export and import is ruled by countries exporting goods in which they have comparative advantage and importing goods in which they have a comparative disadvantage.

Ricardo’s theory of comparative advantage, however, didn’t explain why the comparative advantage was the way it was. In the beginning of the 20th century, two Swedish economists — Eli Heckscher and Bertil Ohlin — presented a theory/model/theorem according to which the comparative advantages arose from differences in factor endowments between countries. Countries have a comparative advantages in producing goods that use up production factors that are most abundant in the different countries. Countries would a fortiori mostly export goods that used the abundant factors of production and import goods that mostly used factors of productions that were scarce.

The Heckscher-Ohlin theorem –as do the elaborations on in it by e.g. Vanek, Stolper and Samuelson — builds on a series of restrictive and unrealistic assumptions. The most critically important — beside the standard market clearing equilibrium assumptions — are

(1) Countries use identical production technologies.

(2) Production takes place with a constant returns to scale technology.

(3) Within countries the factor substitutability is more or less infinite.

(4) Factor-prices are equalised (the Stolper-Samuelson extension of the theorem).

These assumptions are, as almost all empirical testing of the theorem has shown, totally unrealistic. That is, they are empirically false. 

That said, one could indeed wonder why on earth anyone should be interested in applying this theorem to real world situations. As so many other mainstream mathematical models taught to economics students today, this theorem has very little to do  with the real world.

From a methodological point of view one can, of course, also wonder, how we are supposed to evaluate tests of a theorem building on known to be false assumptions. What is the point of such tests? What can those tests possibly teach us? From falsehoods anything logically follows.

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.

Some people have trouble with the fact that from allowing false assumptions mainstream economists can generate whatever conclusions they want in their models.

But that’s really nothing very deep or controversial. What I’m referring to is the well-known ‘principle of explosion,’ according to which if both a statement and its negation are considered true, any statement whatsoever can be inferred.

Whilst tautologies, purely existential statements and other nonfalsifiable statements assert, as it were, too little about the class of possible basic statements, self-contradictory statements assert too much. From a self-contradictory statement, any statement whatsoever can be validly deduced. Consequently, the class of its potential falsifiers is identical with that of all possible basic statements: it is falsified by any statement whatsoever.

On the question of tautology, I think it is only fair to say that the way axioms and theorems are formulated in mainstream (neoclassical) economics, they are often made tautological and informationally totally empty.

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.

Why people have no faith in economics anymore

In recent years the public has lost faith the in the economics profession.

One reason for the lack of faith is the failure to predict the Great Recession, but the public’s dismissal of macroeconomists is based upon more than the failure to foresee the dangers the housing bubble posed for the economy. It is also due to false promises about the benefits to the working class from globalization, tax cuts for the wealthy, and trade agreements – promises that were often used to support ideological and political goals or to serve special interests.

In retrospect the evidence for the housing bubble was easy to see and a few people tried to sound the alarm but they were widely dismissed. Even when the warnings were taken seriously the belief was that the consequences from a housing bubble collapse would be relatively minor and confined to the housing sector. Very few people believed there would be a deep and long-lasting recession …

The arguments used to justify austerity policies put forth both by reputable economists and promoted by those with an ideological agenda for smaller government – the idea that reducing government deficits would create a confidence effect and stimulate the economy – turned out to be wrong. Repeated warnings about inflation due to quantitative easing from economists with standing in the profession, warnings that proved false again and again, provided ammunition to those with a vendetta against the Fed.

If we go back a bit further in time, it’s easy to find more examples. Globalization and international trade were supposed to make us all better off. There would be adjustment costs along the way that would hopefully be offset by government policies to help those who paid the cost of the transition, but in the long-run more trade would lift all boats. But that hasn’t happened. Wages for the majority of people have stagnated, there have been large job displacements that government policy has not done much to address, and the gains have gone to those at the top of the income distribution.

Tax cuts for the wealthy were supposed to stimulate growth and make everyone better off. There was dispute about this within the profession, but there were also many economists who provided intellectual support for the claim that tax cuts will create growth and widespread prosperity. The evidence from the Bush and Reagan tax cuts does not support this claim, but it is still made by some economists and this gives those who are serving wealthy interests or who want to force government to shrink by starving it of revenue the cover they need for their arguments …

We do need more humility about what we do and do not know, more willingness to change our minds when the evidence disagrees with our favorite theoretical model, and the willingness to acknowledge disagreement within the profession. But most of all we need to take a strong stand against those inside and outside the profession who misuse economic theory and empirical results for political and ideological purposes.

Mark Thoma

People who have their heads fuddled with nonsense

The Conservative belief that there is some law of nature which prevents men from being employed, that it is “rash” to employ men, and that it is financially ‘sound’ to maintain a tenth of the population in idleness for an indefinite period, is crazily improbable – the sort of thing which no man could believe who had not had his head fuddled with nonsense for years and years … Our main task, therefore, will be to confirm the reader’s instinct that what seems sensible is sensible, and what seems nonsense is nonsense. We shall try to show him that the conclusion, that if new forms of employment are offered more men will be employed, is as obvious as it sounds and contains no hidden snags; that to set unemployed men to work on useful tasks does what it appears to do, namely, increases the national wealth; and that the notion, that we shall, for intricate reasons, ruin ourselves financially if we use this means to increase our well-being, is what it looks like – a bogy.

John Maynard Keynes (1929)

Bad ideas never die — Greg Mankiw’s Alesina fairy tale

So what’s wrong with the economy? …

A 2002 study of United States fiscal policy by the economists Olivier Blanchard and Roberto Perotti found that ‘both increases in taxes and increases in government spending have a strong negative effect on private investment spending.’ They noted that this finding is ‘difficult to reconcile with Keynesian theory.’

Consistent with this, a more recent study of international data by the economists Alberto Alesina and Silvia Ardagna found that ‘fiscal stimuli based on tax cuts are more likely to increase growth than those based on spending increases.’

Greg Mankiw

From Mankiw’s perspective ‘the Alesina work suggests a still plausible hypothesis.’

Hmm …

Austerity policies not only generate substantial welfare costs due to supply-side channels, they also hurt demand — and thus worsen employment and unemployment.The notion that fiscal consolidations can be expansionary (that is, raise output and employment), in part by raising private sector confidence and investment, has been championed by, among others, Harvard economist Alberto Alesina in the academic world and by former European Central Bank President Jean-Claude Trichet in the policy arena. However, in practice, episodes of fiscal consolidation have been followed, on average, by drops rather than by expansions in output. On average, a consolidation of 1 percent of GDP increases the long-term unemployment rate by 0.6 percentage point and raises by 1.5 percent within five years the Gini measure of income inequality.

Jonathan Ostry, Prakash Loungani, and David Furceri

Modern economics — the victory of technique over substance

Modern economics is sick. Economics has increasingly become an intellectual game played for its own sake and not for its practical consequences for understanding the economic world. Economists have converted the subject into a sort of social mathematics in which analytical rigour is everything and practical relevance is nothing. To pick up a copy of The American Economic Review or The Economic Journal these days is to wonder whether one has landed on a strange planet in which tedium is the deliberate objective of professional publication. Economics was once condemned as “the dismal science” but the dismal science of yesterday was a lot less dismal than the soporific scholasticism of today …

If there is such a thing as “original sin” in economic methodology, it is the worship of the idol of the mathematical rigour invented by Arrow and Debreu in 1954 and then canonized by Debreu in his Theory of Value five years later, probably the most arid and pointless book in the entire literature of economics.

The result of all this is that we now understand almost less of how actual markets work than did Adam Smith or even Léon Walras. We have forgotten that markets require market-makers, that middlemen have to hold inventories to allow markets to function, that markets need to be organized and that property rights need to be defined and enforced if markets are to get started at all. We have even forgotten that markets adjust as often in terms of quantities rather than prices, as in labour markets and customer commodity markets, as Alfred Marshall knew very well but Walras overlooked; so well have we forgotten that fact that a whole branch of economics sprang up in the 1960s and 70s to provide “microfoundations” for Keynesian macroeco- nomics, that is, some ad hoc explanation for the fact that a decline in aggregate demand causes unemployment at the same real wage and not falling real wages at the same level of employment …

Indeed, much of modern microeconomics might be fairly described as a kind of geography that consists entirely of images of cities but providing no maps of how to reach a city either from any other city or from the countryside.

Mark Blaug

Mark Blaug (1927-2011) did more than any other single person to establish the philosophy and methodology of economics a respected subfield within economics. His path-breaking The methodology of economics (1980) is still a landmark — and the first textbook on economic methodology yours truly had to read as student.

Mainstream — neoclassical — economics has become increasingly irrelevant to the understanding of the real world. The main reason for this irrelevance is the failure of economists to match their deductive-axiomatic methods with their subject.

It is — sad to say — a fact that within mainstream economics internal validity is everything and external validity 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.

Good Hayek vs. Bad Hayek

The source of confusion is that there was a Good Hayek and a Bad Hayek. The Good Hayek was a serious scholar who was particularly interested in the role of knowledge in the economy (and in the rest of society). Since knowledge—about technological possibilities, about citizens’ preferences, about the interconnections of these, about still more—is inevitably and thoroughly decentralized, the centralization of decisions is bound to generate errors and then fail to correct them. The consequences for society can be calamitous, as the history of central planning confirms. That is where markets come in. All economists know that a system of competitive markets is a remarkably efficient way to aggregate all that knowledge while preserving decentralization.

The Good Hayek also knew that unrestricted laissez-faire is unworkable. It has serious defects: successful actors reach for monopoly power, and some of them succeed in grasping it; better-informed actors can exploit the relatively ignorant, creating an inefficiency in the process; the resulting distribution of income may be grossly unequal and widely perceived as intolerably unfair; industrial market economies have been vulnerable to excessively long episodes of unemployment and underutilized capacity, not accidentally but intrinsically; environmental damage is encouraged as a way of reducing private costs—the list is long …

The Bad Hayek emerged when he aimed to convert a wider public. Then, as often happens, he tended to overreach, and to suggest more than he had legitimately argued. The Road to Serfdom was a popular success but was not a good book. Leaving aside the irrelevant extremes, or even including them, it would be perverse to read the history, as of 1944 or as of now, as suggesting that the standard regulatory interventions in the economy have any inherent tendency to snowball into “serfdom.” The correlations often run the other way.

Robert Solow