Microfoundations — neither law, nor true

8 April, 2014 at 10:49 | Posted in Economics | 6 Comments

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Defenders of microfoundations and its rational expectations equipped representative agent’s intertemporal optimization often argue as if sticking with simple representative agent macroeconomic models doesn’t impart a bias to the analysis. I unequivocally reject that unsubstantiated view, and have given the reasons why here.

These defenders often also maintain that there are no methodologically coherent alternatives to microfoundations modeling. That allegation is of course difficult to evaluate, substantially hinging on how coherence is defined. But one thing I do know, is that the kind of microfoundationalist macroeconomics that New Classical economists and “New Keynesian” economists are pursuing, are not methodologically coherent according to the standard coherence definition (see e. g. here). And that ought to be rather embarrassing for those ilks of macroeconomists to whom axiomatics and deductivity is the hallmark of science tout court.

The fact that Lucas introduced rational expectations as a consistency axiom is not really an argument to why we should accept it as an acceptable assumption in a theory or model purporting to explain real macroeconomic processes (see e. g. here). And although virtually any macroeconomic empirical claim is contestable, so is any claim in micro (see e. g. here).

On this issue I think Paul Krugman comes closer to truth than his “New Keynesian” buddies with his remark that

what we call “microfoundations” are not like physical laws. Heck, they’re not even true.

Aggregate production functions and other neoclassical fairy tales

7 April, 2014 at 15:34 | Posted in Economics | 4 Comments

When one works – as one must at an aggregate level – with quantities measured in value terms, the appearance of a well-behaved aggregate production function tells one nothing at all about whether there really is one. Such an appearance stems from the accounting identity that relates the value of outputs to the value of inputs – nothing more.

Frank%20300dpi-1v2All these facts should be well known. They are not, or, if they are, their implications are simply ignored by macroeconomists who go on treating the aggregate production function as the most fundamental construct of neoclassical macroeconomics …

The consequences of the non-existence of aggregate production functions have been too long overlooked. I am reminded of the story that, during World War II, a sign in an airplane manufacturing plant read: “The laws of aerodynamics tell us that the bumblebee cannot fly. But the bumblebee does fly, and, what is more, it makes a little honey each day.” I don’t know about bumblebees, but any honey supposedly made by aggregate production functions may well be bad for one’s health.

Attempts to explain the impossibility of using aggregate production functions in practice are often met with great hostility, even outright anger. To that I say … that the moral is: “Don’t interfere with fairytales if you want to live happily ever after.”

Franklin Fisher

On capital, neoclassical parables and facts of life

7 April, 2014 at 14:12 | Posted in Economics | Leave a comment

Pathology illuminates healthy physiology. Pasinetti, Morishima, Bruno-Burmeister-Sheshinski, Garegnani merit our gratitude for demonstrating that reswitching is a logical possibility in any technology, indecomposable or decomposable. Reswitching, whatever its empirical likelihood, does alert us to several vital possibilities:

Lower interest rates may bring lower steady-state consumption and lower capital/output ratios, and the transition to such lower interest rate can involve denial of diminishing returns and entail reverse capital deepening in which current consumption is augmented rather than sacrificed.

capitalThere often turns out to be no unambiguous way of character-izing different processes as more “capital-intensive,” more “mechanized,” more “roundabout,” except in the ex post tautological sense of being adopted at a lower interest rate and involving a higher real wage. Such a tautological labeling is shown, in the case of reswitching, to lead to inconsistent ranking between pairs of unchanged technologies, depending upon which interest rate happens to prevail in the market.

If all this causes headaches for those nostalgic for the old time parables of neoclassical writing, we must remind ourselves that scholars are not born to live an easy existence. we must respect, and appraise, the facts of life.

Paul Samuelson

Just felt it was time to refresh the memory of some of my neoclassical colleagues …

PISA-resultat och antagningskrav

7 April, 2014 at 10:51 | Posted in Education & School | Leave a comment

Siffror som Agenda låtit Universitets- och högskolerådet ta fram visar att vårterminen 2014 antogs 25 sökande med under 0,1 poäng på högskoleprovet. Det innebär att i stort sett vem som helst med grundläggande behörighet kan komma in.

Det finns attraktiva lärarutbildningar med höga antagningskrav. Men det finns också de som nästan inte har några andra krav än godkända gymnasiebetyg.

pisa20002012På ett par lärar-utbildningar räckte det i höstas med 0,05 poäng. Av dem som skrev hög-skoleprovet var det bara två promille som hade så dåliga resultat. Även nu på vårterminen fanns en utbildning där 0,05 poäng räckte.

Regeringen föreslog nyligen att gränsen för att antas till högskolan ska höjas till 0,5 poäng från högskoleprovet. Maxpoängen som går att få är 2,0.

SVT Nyheter

The capital controversy — when ignorance is bliss

6 April, 2014 at 17:46 | Posted in Economics | Leave a comment

joanThe production function has been a powerful instrument of miseducation.
The student of economic theory is taught to write Q = f(L, K) where L is a quantity of labor, K a quantity of capital and Q a rate of output of commodities. He is instructed to assume all workers alike, and to measure L in man-hours of labor; he is told something about the index-number problem in choosing a unit of output; and then he is hurried on to the next question,
in the hope that he will forget to ask in what units K is measured. Before he ever does ask, he has become a professor, and so sloppy habits of thought are handed on from one generation to the next.

Joan Robinson The Production Function and the Theory of Capital (1953)

Still No. 1

5 April, 2014 at 18:48 | Posted in Varia | Leave a comment

 

Piketty and the Cambridge capital controversy

5 April, 2014 at 17:40 | Posted in Economics | 7 Comments

Piketty wants to provide a theory relevant to growth, which requires physical capital as its input. And yet he deploys an empirical measure that is unrelated to productive physical capital and whose dollar value depends, in part, on the return on capital. Where does the rate of return come from? Piketty never says. He merely asserts that the return on capital has usually averaged a certain value, say 5 percent on land in the nineteenth century, and higher in the twentieth.

17197686-abstract-word-cloud-for-cambridge-capital-controversy-with-related-tags-and-termsThe basic neoclassical theory holds that the rate of return on capital depends on its (marginal) productivity. In that case, we must be thinking of physical capital—and this (again) appears to be Piketty’s view. But the effort to build a theory of physical capital with a technological rate-of-return collapsed long ago, under a withering challenge from critics based in Cambridge, England in the 1950s and 1960s, notably Joan Robinson, Piero Sraffa, and Luigi Pasinetti.

Piketty devotes just three pages to the “Cambridge-Cambridge” controversies, but they are important because they are wildly misleading. He writes:

“Controversy continued . . . between economists based primarily in Cambridge, Massachusetts (including [Robert] Solow and [Paul] Samuelson) . . . and economists working in Cambridge, England . . . who (not without a certain confusion at times) saw in Solow’s model a claim that growth is always perfectly balanced, thus negating the importance Keynes had attributed to short-term fluctuations. It was not until the 1970s that Solow’s so-called neoclassical growth model definitively carried the day.”

But the argument of the critics was not about Keynes, or fluctuations. It was about the concept of physical capital and whether profit can be derived from a production function. In desperate summary, the case was three-fold. First: one cannot add up the values of capital objects to get a common quantity without a prior rate of interest, which (since it is prior) must come from the financial and not the physical world. Second, if the actual interest rate is a financial variable, varying for financial reasons, the physical interpretation of a dollar-valued capital stock is meaningless. Third, a more subtle point: as the rate of interest falls, there is no systematic tendency to adopt a more “capital-intensive” technology, as the neoclassical model supposed.

In short, the Cambridge critique made meaningless the claim that richer countries got that way by using “more” capital. In fact, richer countries often use less apparent capital; they have a larger share of services in their output and of labor in their exports—the “Leontief paradox.” Instead, these countries became rich—as Pasinetti later argued—by learning, by improving technique, by installing infrastructure, with education, and—as I have argued—by implementing thoroughgoing regulation and social insurance. None of this has any necessary relation to Solow’s physical concept of capital, and still less to a measure of the capitalization of wealth in financial markets.

There is no reason to think that financial capitalization bears any close relationship to economic development. Most of the Asian countries, including Korea, Japan, and China, did very well for decades without financialization; so did continental Europe in the postwar years, and for that matter so did the United States before 1970.

And Solow’s model did not carry the day. In 1966 Samuelson conceded the Cambridge argument!

James K. Galbraith

Forecasting alchemy

5 April, 2014 at 12:08 | Posted in Economics, Statistics & Econometrics | Leave a comment

Businesswoman standing on a ladder looking through binocularsIn New York State, Section 899 of the Code of Criminal Procedure provides that persons “Pretending to Forecast the Future” shall be considered disorderly under subdivision 3, Section 901 of the Code and liable to a fine of $250 and/or six months in prison.

Although the law does not apply to “ecclesiastical bodies acting in good faith and without fees,” I’m not sure where that leaves econometricians and other forecasters …

I came to think about this nineteenth century New York law the other day when interviewed by a public radio journalist working on a series on Great Economic ThinkersWe were discussing the monumental failures of the predictions-and-forecasts-business. But — the journalist asked — if these cocksure economists with their “rigorous” and “precise” mathematical-statistical-econometric models are so wrong again and again — why do they persist wasting time on it?

In a discussion on uncertainty and the hopelessness of accurately modeling what will happen in the real world – in M. Szenberg’s Eminent Economists: Their Life Philosophies – Nobel laureate Kenneth Arrow comes up with what is probably the right answer:

It is my view that most individuals underestimate the uncertainty of the world. This is almost as true of economists and other specialists as it is of the lay public. To me our knowledge of the way things work, in society or in nature, comes trailing clouds of vagueness … Experience during World War II as a weather forecaster added the news that the natural world as also unpredictable. cloudsAn incident illustrates both uncer-tainty and the unwilling-ness to entertain it. Some of my colleagues had the responsi-bility of preparing long-range weather forecasts, i.e., for the following month. The statisticians among us subjected these forecasts to verification and found they differed in no way from chance. The forecasters themselves were convinced and requested that the forecasts be discontinued. The reply read approximately like this: ‘The Commanding General is well aware that the forecasts are no good. However, he needs them for planning purposes.’

Into Eternity

5 April, 2014 at 11:49 | Posted in Varia | Leave a comment

 

Is economics ripe for disruption?

4 April, 2014 at 17:00 | Posted in Economics | 1 Comment

It was, of all people, Elizabeth Windsor who laid the charge most forcefully. Opening a new building at the LSE, weeks after Lehman Brothers imploded, she asked one of the dons why no one had seen the meltdown coming. In the years since, it has often seemed as if students are more serious than their lecturers about pursuing the monarch’s concern.

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Undergraduates at Sheffield and Cambridge have set out to rattle the foundation stones of their discipline. In Manchester, they went further, organising the Post-Crash Economics Society and securing more eclectic instruction, through a new Bubbles, Panics and Crashes module. Covering the former Fed boss, Ben Bernanke, as well as the interwar Marxist, Kalecki, the course was not reducible to right or left. It offered something closer to economics as understood in Keynes’s Cambridge. Manchester, however, has now declined to accredit the course, and instead opted to pull the plug …

The failure to spot the crisis raised wider questions about the discipline’s usefulness. It can shelter behind unavoidable ambiguities regarding the price of both labour and capital. Will workers respond to income tax cuts by striving for the extra earnings they can now keep or by skiving, on the basis that they can now afford to take more time off? Do high interest rates induce savers to scrimp or encourage them to go out and blow their extra return? No one can say without interrogating the data – which good economists do try to do. But hopes of clear answers are retarded by departments that treat the subject as a branch of applied mathematics, and by practitioners less concerned with the insight than the arithmetical tractability of their models.

These shortcomings go back to “the marginal revolution”, which jettisoned the dynamic, sweeping preoccupations of 19th century classical political economy in favour of a narrower but more precise concern with movements between market equilibrium. But the big questions that concerned Mill, Marx and Smith are now rearing their heads afresh …

Now Thomas Piketty – who spent long years, during which the mainstream neglected inequality, mapping the distribution of income – is making waves with Capital in the 21st Century. Nodding at Marx, that title helps explain the attention, but his decidedly classical emphasis on historical dynamics in determining who gets what resonates in a world where an increasing proportion of citizens are feeling fleeced by the elite. The tide of intellectual history is on the side of Manchester’s students.

The Guardian

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