Applied econometrics

15 February, 2019 at 10:06 | Posted in Economics | 1 Comment

The applied econometrician is like a farmer who notices that the yield is
somewhat higher under the trees where birds roost, and he uses this for evidence
that bird droppings increase the yield. However, when he presents his findings … another farmer … objects that he used the same data but came up with the conclusion that moderate amounts of shade increase the yields … A bright chap … then observes that these two hypotheses are indistinguishable, given the available data …

51pDIwWiNLL__SX313_BO1,204,203,200_The obvious response of course, albeit one that econometricians occupied with
fitting a line to given sets of data rarely contemplate, is to add the ‘available
data.’ Specifically, the aim must be to draw consequences for, and seek out
observations on, actual phenomena which allow the causal factor responsible to
be identified. If, for example, bird droppings is a relevant causal factor then we
could expect higher yields wherever birds roost. Perhaps there is a telegraph
wire that crosses the field which is heavily populated with roosting birds, but
which provides only negligible shade … The fact that it is not possible to
state categorically at this abstract level the precise conditions under which
substantive theories can be selected amongst, i.e., without knowing the contents
of the theories themselves or the nature or context of the conditions upon which
they bear, is an unfortunate fact of all science …

Science is a messy business. It requires an abundance of ingenuity, as well as patience, along with skills that may need to be developed on the job.

What is Post-Keynesian economics?

14 February, 2019 at 17:40 | Posted in Economics | Leave a comment


Winners Take All

13 February, 2019 at 19:07 | Posted in Economics | 2 Comments


Understanding government debts and deficits

10 February, 2019 at 00:45 | Posted in Economics | 28 Comments

The balanced budget paradox is probably one of the most devastating phenomena haunting our modern economies. The harder politicians — usually on the advice of establishment economists — try to achieve balanced budgets for the public sector, the less likely they are to succeed in their endeavour. And the more the citizens have to pay for the concomitant austerity policies these wrong-headed politicians and economists recommend as “the sole solution.”

One of the most effective ways of clearing up this most serious of all semantic confusions is to point out that private debt differs from national debt in being external … A variant of the false analogy is the declaration that national debt puts an unfair burden on our children, who are thereby made to pay for our extravagances. Very few economists need to be reminded that if our children or grandchildren repay some of the national debt these payments will be made to our children or grandchildren and to nobody else. Taking them altogether they will no more be impoverished by making the repayments than they will be enriched by receiving them.

Abba Lerner The Burden of the National Debt (1948)

Few issues in politics and economics are nowadays more discussed — and less understood — than public debt. Many raise their voices to urge for reducing the debt, but few explain why and in what way reducing the debt would be conducive to a better economy or a fairer society. And there are no limits to all the — especially macroeconomic — calamities and evils a large public debt is supposed to result in — unemployment, inflation, higher interest rates, lower productivity growth, increased burdens for subsequent generations, etc., etc.

But the truth is that public debt is normally nothing to fear, especially if it is financed within the country itself (but even foreign loans can be beneficent for the economy if invested in the right way). Some members of society hold bonds and earn interest on them, while others have to pay the taxes that ultimately pay the interest on the debt. The debt is not a net burden for society as a whole since the debt cancel itself out between the two groups. If the state issues bonds at a low-interest rate, unemployment can be reduced without necessarily resulting in strong inflationary pressure. And the inter-generational burden is also not a real burden since — if used in a suitable way — the debt, through its effects on investments and employment, actually makes future generations net winners. There can, of course, be unwanted negative distributional side effects for the future generation, but that is mostly a minor problem since when our children and grandchildren repay the national debt these payments will be made to our children and grandchildren.

To both Keynes and Lerner, it was evident that the state has the ability to promote full employment and a stable price level – and that it should use its powers to do so. If that means that it has to take on debt and (more or less temporarily) underbalance its budget – so let it be! Public debt is neither good nor bad. It is a means to achieve two over-arching macroeconomic goals – full employment and price stability. What is sacred is not to have a balanced budget or running down public debt per se, regardless of the effects on the macroeconomic goals. If ‘sound finance,’ austerity and balanced budgets means increased unemployment and destabilizing prices, they have to be abandoned.

Discussing within which margins public debt is feasible, the focus today is solely on the upper limit of indebtedness, and very few ask the question if maybe there is also a problem if public debt becomes too low.

To guarantee a well-functioning secondary market in bonds it is essential that the government has access to a functioning market. If turnover and liquidity in the secondary market become too small, increased volatility and uncertainty will, in the long run, lead to an increase in borrowing costs. Ultimately there’s even a risk that market makers would disappear, leaving bond market trading to be operated solely through brokered deals. As a kind of precautionary measure against this eventuality, it may be argued – especially in times of financial turmoil and crises — that it is necessary to increase government borrowing and debt to ensure – in a longer run – good borrowing preparedness and a sustained (government) bond market.

To view government debts in terms of the ‘functional finance’ concept introduced by Abba Lerner, is to consider their role in the macroeconomic balance of the economy. In simple, bare bones terms, the function of government debts that is significant for the macroeconomic health of an economy is that they provide the assets into which individuals can put whatever accumulated savings they attempt to set aside in excess of what can be wisely invested in privately owned real assets. A debt that is smaller than this will cause the attempted excess savings, by being reflected in a reduced level of consumption outlays, to be lost in reduced real income and increased unemployment.

William Vickrey

Paul Samuelson — an economist in ‘the business of dishonesty’

8 February, 2019 at 00:00 | Posted in Economics | 7 Comments

I think there is an element of truth in the view that the superstition that the budget must be balanced at all times [is necessary]. Once it is debunked, [it] takes away one of the bulwarks that every society must have against expenditure out of control. There must be discipline in the allocation of resources or you will have anarchistic chaos and inefficiency. And one of the functions of old fashioned religion was to scare people by sometimes what might be regarded as myths into behaving in a way that the long-run civilized life requires. We have taken away a belief in the intrinsic necessity of balancing the budget if not in every year, [and then] in every short period of time. If Prime Minister Gladstone came back to life he would say “oh, oh what you have done” and James Buchanan argues in those terms. I have to say that I see merit in that view.

Paul Samuelson

Samuelson’s statement makes me come to think of the following passage in Keynes’ General Theory:

The ideas of economists and political philosophers, both when they are right and when they are wrong, are more powerful than is com­monly understood. Indeed the world is ruled by little else. Practical men, who believe themselves to be exempt from any intellectual influences, are usually the slaves of some defunct economist. Madmen in authori­ty, who hear voices in the air, are distilling their frenzy from some academic scribbler of a few years back.

MMT for beginners

7 February, 2019 at 22:15 | Posted in Economics | 8 Comments


Fallacies of financial fundamentalism

6 February, 2019 at 16:43 | Posted in Economics | 3 Comments

Fallacy 2
Urging or providing incentives for individuals to try to save more is said to stimulate investment and economic growth.

Again, actually the exact reverse is true. In a money economy, for most individuals a decision to try to save more means a decision to spend less; less spending by a saver means less income and less saving for the vendors and producers, and aggregate saving is not increased, but diminished as vendors in turn reduce their purchases, national income is reduced and with it national saving. A given individual may indeed succeed in increasing his own saving, but only at the expense of reducing the income and saving of others by even more …

Saving does not create “loanable funds” out of thin air. There is no presumption that the additional bank balance of the saver will increase the ability of his bank to extend credit by more than the credit supplying ability of the vendor’s bank will be reduced … Attempted saving, with corresponding reduction in spending, does nothing to enhance the willingness of banks and other lenders to finance adequately promising investment projects. With unemployed resources available, saving is neither a prerequisite nor a stimulus to, but a consequence of capital formation, as the income generated by capital formation provides a source of additional savings.

Fallacy 3
Government borrowing is supposed to “crowd out” private investment.

The current reality is that on the contrary, the expenditure of the borrowed funds (unlike the expenditure of tax revenues) will generate added disposable income, enhance the demand for the products of private industry, and make private investment more profitable. As long as there are plenty of idle resources lying around, and monetary authorities behave sensibly, (instead of trying to counter the supposedly inflationary effect of the deficit) those with a prospect for profitable investment can be enabled to obtain financing. Under these circumstances, each additional dollar of deficit will in the medium long run induce two or more additional dollars of private investment. The capital created is an increment to someone’s wealth and ipso facto someone’s saving. “Supply creates its own demand” fails as soon as some of the income generated by the supply is saved, but investment does create its own saving, and more. Any crowding out that may occur is the result, not of underlying economic reality, but of inappropriate restrictive reactions on the part of a monetary authority in response to the deficit.

William Vickrey Fifteen Fatal Fallacies of Financial Fundamentalism

Veckans dumstrut

6 February, 2019 at 11:29 | Posted in Economics, Politics & Society | 3 Comments

dumstrutI programmet Ekdal och Ekdal häromkvällen fick Sveriges finansminister — Magdalena Andersson — på bästa sändningstid möjlighet förklara hur vi ska kunna minska klyftorna i Sverige. Till min — och säkert flera andras — stora förvåning verkade fru Andersson vara mest intresserad av att försöka frammåla en bild av att problemen egentligen inte är så stora eftersom socialdemokratin har hållit den ‘svenska modellen’ — för att i grunden skapa ett jämlikt samhälle — levande:

1 Alla ska ha ett arbete med löner som man kan leva på.

2 De rikas och fattigas barn ska gå i lika bra skolor, och de rika och fattiga ha samma tillgång till bra vård och omsorg.

3 Ett progressivt skattesystem ska bidra till att omfördela resurser från rika till mindre välbeställda.

Herre du milde! Och detta grodors plums och ankors plask ska man behöva lyssna till år 2019. Man tager sig för pannan!

Snacka går ju alltid, men det är ändå bättre om man vet vad man pratar om. Så här ser det nämligen ut:

1 Sverige har idag en arbetslöshet på 6%  (för ungdomar 14%) — långt över de nivåer vi när vi verkligen hade en ‘svensk modell’ brukade betrakta som acceptabla.

2 Sverige har idag — som skolverket, skolinspektionen och mängder av internationella rapporter och jämförelser gång på gång visat — en skola som är mer segregerad än någonsin. Senast i förra veckan kunde SvT berätta om vilka förödande konsekvenser friskolor och ett kommunalt huvudmannaskap för skolan får för samhället.

3 I Sverige utgör idag av de samlade skatteintäkterna den progressiva skatten (inkomstskatten) för dem som tjänar mer än 40 000 kronor i månaden bara några enstaka procent av de totala skatteintäkterna. Om något har vi idag snarare ett regressivt skattesystem — ju högre inkomst och förmögenhet folk har, desto mindre betalar de i skatt.

Faktakoll är inte så dåligt och man kan ju tycka att det borde vara en självklarhet för en finansminister. Ska vi klara av att göra något åt den ökade ojämlikheten har vi nog tyvärr inte så mycket att hämta hos politiker som verkar ha noll koll på hur verkligheten ser ut.

Bernard Lietaer (1942 — 2019)

4 February, 2019 at 22:40 | Posted in Economics | Leave a comment


Sad news reached us today that one of our greatest monetary​ thinkers, Bernard Lietaer, has passed away. RIP.

Gary Becker — making nonsense out of economic science

2 February, 2019 at 10:28 | Posted in Economics | 2 Comments

1399387137298The econometrician Henri Theil once said “models are to be used but not to be believed.” I use the rational actor model for thinking about marginal changes but Gary Becker really believed the model. Once, at a dinner with Becker, I remarked that extreme punishment could lead to so much poverty and hatred that it could create blowback. Becker was having none of it. For every example that I raised of blowback, he responded with a demand for yet more punishment …

Alex Tabarrok

straight jacketThe alarm that sets off in my brain when reading Becker is that ‘rational actor models,’ 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.

One could indeed wonder why on earth anyone should be interested in applying that kind of theory to real-world situations. Like so many other mainstream mathematical models taught to economics students today, it has next to nothing 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 theories and models 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 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 modellers 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 follow 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 — of which Gary Becker’s ‘rational actor model’ is a superb example.

Die Macht der Zahlen

31 January, 2019 at 21:03 | Posted in Economics | Leave a comment


Economics and reality

30 January, 2019 at 11:24 | Posted in Economics | 7 Comments

Modern’ economics has become increasingly irrelevant to the understanding of the real world. In his seminal book Economics and Reality (1997), Tony Lawson traced this irrelevance to the failure of economists to match their deductive-axiomatic methods with their subject

It is — sad to say — as relevant today as it was twenty years ago.

It is still 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 is beyond imagination. 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, they really should not be surprised if people say that this is not science, but autism!

Studying mathematics and logic is interesting and fun. It sharpens the mind. In pure mathematics and logic, we do not have to worry about external validity. But economics is not pure mathematics or logic. It’s about society. The real world.

Economics and Reality was a great inspiration to yours truly twenty years ago. It still is.

Så återskapar vi förtroendet för nationalekonomi som vetenskap

29 January, 2019 at 16:26 | Posted in Economics | 4 Comments

varapport2009_3-724x1024Nationalekonomin som vetenskap har världen över förlorat otroligt mycket i prestige och status under senare år. Inte minst på grund av dess oförmåga att se den senaste finansiella krisen i antågande och på grund av dess avsaknad av konstruktiva och hållbara förslag på att ta oss ur krisen.

Hur återskapar vi förtroendet för nationalekonomin?

Fem förändringar är helt avgörande.

(1) Sluta låtsas som om vi har exakta och riktiga svar på allting. För det har vi inte. Vi bygger modeller och teorier där vi på hundradelars procent kan tala om vad värdet på räntan kommer att vara om trettio år. Vi kan kalkylera investeringsrisker och göra exakta framtidsprognoser. Men detta bygger vi på matematiska och statistiska antaganden som ofta har väldigt lite eller inget alls med verkligheten att göra. Genom att inte låtsas om den avgörande skillnaden mellan modell och verklighet invaggar vi människor i en falsk trygghet av att vi har koll på läget. Det har vi inte! Det var denna falska trygghet som aktivt medverkade till finanskrisen år 2008. Vi måste våga erkänna att vi ibland inte vet allt, utan att det finns saker som vi inte ens vet att vi inte vet. All osäkerhet går inte att reducera till kalkylerbar risk.

(2) Sluta upp med den barnsliga övertron på matematikens förmåga att ge svar på viktiga ekonomiska frågor. Matematik ger bara exakta svar på exakta frågor. Men de intressanta och relevanta frågor vi ställs inför på det ekonomiska området är sällan av det slaget. Frågor av typen “är 2 + 2 = 4?” lyser helt med sin frånvaro i verklighetens ekonomi. Istället för en i grunden förfelad tilltro till att abstrakta matematisk-axiomatiska modeller har något av substans att tillföra vår kunskap om samhällsekonomin, hade det varit bättre om vi ägnade oss åt relevanta empiriska studier och observationer.

(3) Sluta upp med tron att vi inom nationalekonomin rör oss med lagar. Med övertron på matematiken följer också en i grunden förfelad tro på att vi inom ekonomin ska och kan ställa upp universella och allmängiltiga lagar av den typen som finns inom exempelvis fysiken eller astronomin. Det kan vi inte. Ekonomi är inget slutet planetsystem eller fysiklab. I verkligheten är det mesta vi kan hoppas på inom ekonomins område att fastslå eventuella tendenser med varierande grad av generaliserbarhet.

(4) Sluta upp att betrakta alla andra samhällsvetenskaper som fattiga kusiner från landet. Nationalekonomin har länge lidit av kraftig hybris. Men “samhällsvetenskapernas drottning” klarar sig inte utan samverkan med andra vetenskaper. Inte minst andra mer evidensbaserade vetenskaper som ekonomisk historia och psykologi har mycket att tillföra nationalekonomin. Mångfald och vidsyn skulle berika en idag alltför autistisk nationalekonomi.

(5) Sluta på det ekonomisk-politiska området upp med att bygga modeller och prognoser på fullständigt verklighetsfrånvända “mikrofundament” med robotliknande “representativa aktörs”-imitationer av över tiden optimerande människor utrustade med “rationella förväntningar”. Detta är ren och skär nonsens. Vi måste bygga våra mikrofundament och makromodeller på antaganden som inte står i uppenbar kontrast till verkligheten. Och i det arbetet måste vi vara ödmjuka nog att inse att psykologi och andra beteendevetenskaper kan bidra med viktiga pusselbitar.

Is money — really — neutral in the long run?

22 January, 2019 at 22:27 | Posted in Economics | 9 Comments

Paul Krugman has repeatedly over the years argued that we should continue to use neoclassical hobby horses like IS-LM and Aggregate Supply-Aggregate Demand models. Here’s one example:

So why do AS-AD? … We do want, somewhere along the way, to get across the notion of the self-correcting economy, the notion that in the long run, we may all be dead, but that we also have a tendency to return to full employment via price flexibility. Or to put it differently, you do want somehow to make clear the notion (which even fairly Keynesian guys like me share) that money is neutral in the long run.

I doubt that Keynes would have been impressed by having his theory being characterized by catchwords like “tendency to return to full employment” and “money is neutral in the long run.”


One of Keynes’s central tenets — in clear contradistinction to the beliefs of mainstream economists — is that there is no strong automatic tendency for economies to move toward full employment levels in monetary economies.

Money doesn’t matter in mainstream macroeconomic models. But in the real world in which we happen to live, money does certainly matter. Money is not neutral and money matters in both the short run and the long run:

The theory which I desiderate would deal … with an economy in which money plays a part of its own and affects motives and decisions, and is, in short, one of the operative factors in the situation, so that the course of events cannot be predicted in either the long period or in the short, without a knowledge of the behaviour of money between the first state and the last. And it is this which we ought to mean when we speak of a monetary economy.

J. M. Keynes A monetary theory of production (1933)

Finland’s Universal Basic Income experiment — an evaluation

20 January, 2019 at 16:29 | Posted in Economics, Politics & Society | Comments Off on Finland’s Universal Basic Income experiment — an evaluation


Results on the first year of the Finnish UBI experiment will become available in a couple of months, and a final report — covering the whole two-year time-span — is scheduled for publication in 2020.

Knut Wicksell — le origini della Teoria Monetaria Moderna

19 January, 2019 at 17:52 | Posted in Economics | 2 Comments

Molti economisti mainstream sembrano pensare che l’idea alla base della Teoria Monetaria Moderna sia nuova e nasca da strane idee economiche.

Nuova? Strane idee? Che ne diciamo di leggere uno dei grandi fondatori dell’economia neoclassica – Knut Wicksell. Questo è ciò che Wicksell scrisse nel 1898 sui “sistemi di puro credito” in Interesse Monetario e Prezzi dei Beni (Geldzins und Güterpreise), 1936 (1898), p. 68f:

wicksell_-_geldzins_und_güterpreise,_1936_-_5770488E’ possibile andare oltre. Non c’è affatto alcun bisogno reale di moneta se un pagamento tra due individui può essere compiuto semplicemente trasferendo la somma appropriata di denaro nei registri bancari …

Un sistema di puro credito non è ancora … stato completamente sviluppato in questa forma. Ma qua e là si può trovare nella veste, alquanto diversa, del sistema delle banconote…

Intendiamo perciò, come fondamento per la discussione che segue, immaginare una situazione in cui il denaro in realtà non circola affatto, né in forma di moneta. … né in forma di banconote, ma dove tutti i pagamenti domestici vengono effettuati per mezzo del sistema di giro [bancario – vaglia bancario ndt] e di trasferimenti contabili. Un’analisi approfondita di questo caso puramente immaginario mi sembra utile, perché fornisce una precisa antitesi alla situazione, anch’essa immaginaria di un sistema di contante puro, in cui il credito non svolge alcun ruolo a prescindere [l’esatto equivalente del modello neoclassico frequentemente assunto di “pagamento anticipato” – LPS] …

Per ragioni semplificative, dobbiamo quindi assumere che l’intero sistema monetario di un paese è nelle mani di un unico istituto di credito, dotato di un adeguato numero di sportelli, in cui ogni individuo economico indipendente detiene un conto col quale può firmare assegni.

Quello che la Teoria Monetaria Moderna (MMT) sostiene è esattamente quello che Wicksell provava ad ipotizzare oltre un secolo fa. La differenza è che oggi l’“economia di puro credito” è una realtà e non solo una curiosità teoretica – la MMT descrive un sistema di moneta legale che [al giorno d’oggi] è in funzione in quasi tutti i paesi del mondo.

In tempi moderni le valute legali sono completamente basate su monete fiat. Le valute non hanno più valore intrinseco (come oro e argento). Ciò che dà loro valore è sostanzialmente il semplice fatto che, tramite esse, si devono pagare le tasse. Ciò consente ai governi di esercitare una sorta di “monopolio del business” della valuta, della quale essi non possono mai rimanere senza. A maggior ragione, la spesa diventa l’azione primaria e la tassazione e l’indebitamento sono degradati ad atti secondari. Se abbiamo una depressione, la soluzione, quindi, non è l’austerità. E’ la spesa. I Deficit di bilancio non sono il problema principale, dal momento che la moneta fiat significa che i governi possono sempre emetterne a sufficienza.

Lars P Syll

Paul Krugman — a methodological critique

16 January, 2019 at 16:03 | Posted in Economics | 50 Comments

Alex Rosenberg — chair of the philosophy department at Duke University and renowned economic methodologist — has an interesting article on What’s Wrong with Paul Krugman’s Philosophy of Economics in 3:AM Magazine. Writes Rosenberg:

theoryKrugman writes: “So how do you do useful economics? In general, what we really do is combine maximization-and-equilibrium as a first cut with a variety of ad hoc modifications reflecting what seem to be empirical regularities about how both individual behavior and markets depart from this idealized case.”

But if you ask the New Classical economists, they’ll say, this is exactly what we do—combine maximizing-and-equilibrium with empirical regularities …

One thing that’s missing from Krugman’s treatment of economics is the explicit recognition of what Keynes and before him Frank Knight, emphasized: the persistent presence of enormous uncertainty in the economy … Why is uncertainty so important? Because the more of it there is in the economy the less scope for successful maximizing and the more unstable are the equilibria the economy exhibits, if it exhibits any at all …

Along with uncertainty, the economy exhibits pervasive reflexivity: expectations about the economic future tend to actually shift that future … When combined, uncertainty and reflexivity together greatly limit the power of maximizing and equilibrium to do predictively useful economics. Reflexive relations between future expectations and outcomes are constantly breaking down at times and in ways about which there is complete uncertainty.

I think Rosenberg is on to something important here regarding Krugman’s neglect of methodological reflection.

When Krugman responded to my critique of IS-LM this hardly came as a surprise.  As Rosenberg notes, Krugman works with a very simple modelling dichotomy — either models are complex or they are simple. For years now, self-proclaimed “proud neoclassicist” Paul Krugman has in endless harping on the same old IS-LM string told us about the splendour of the Hicksian invention — so, of course, to Krugman simpler models are always preferred.

In a post on his blog, Krugman has argued that ‘Keynesian’ macroeconomics more than anything else “made economics the model-oriented field it has become.” In Krugman’s eyes, Keynes was a “pretty klutzy modeler,” and it was only thanks to Samuelson’s famous 45-degree diagram and Hicks’s IS-LM that things got into place. Although admitting that economists have a tendency to use ”excessive math” and “equate hard math with quality” he still vehemently defends — and always have — the mathematization of economics:

I’ve seen quite a lot of what economics without math and models looks like — and it’s not good.

Sure, ‘New Keynesian’ economists like Krugman — and their forerunners, ‘Keynesian’ economists like Paul Samuelson and (young) John Hicks — certainly have contributed to making economics more mathematical and “model-oriented.”

wrong-tool-by-jerome-awBut if these math-is-the-message-modellers aren’t able to show that the mechanisms or causes that they isolate and handle in their mathematically formalized macromodels are stable in the sense that they do not change when we “export” them to our “target systems,” these mathematical models do only hold under ceteris paribus conditions and are consequently of limited value to our understandings, explanations or predictions of real economic systems.

When it comes to modelling philosophy, Paul Krugman has earlier defended his position in the following words (my italics):

I don’t mean that setting up and working out microfounded models is a waste of time. On the contrary, trying to embed your ideas in a microfounded model can be a very useful exercise — not because the microfounded model is right, or even better than an ad hoc model, but because it forces you to think harder about your assumptions, and sometimes leads to clearer thinking. In fact, I’ve had that experience several times.

The argument is hardly convincing. If people put that enormous amount of time and energy that they do into constructing macroeconomic models, then they really have to be substantially contributing to our understanding and ability to explain and grasp real macroeconomic processes. If not, they should – after somehow perhaps being able to sharpen our thoughts – be thrown into the waste-paper-basket (something the father of macroeconomics, Keynes, used to do), and not as today, being allowed to overrun our economics journals and giving their authors celestial academic prestige.

Krugman’s explications on this issue are really interesting also because they shed light on a kind of inconsistency in his art of argumentation. For years now, Krugman has repeatedly criticized mainstream economics for using too much (bad) mathematics and axiomatics in their model-building endeavours. But when it comes to defending his own position on various issues he usually himself ultimately falls back on the same kind of models. In his End This Depression Now — just to take one example — Paul Krugman maintains that although he doesn’t buy “the assumptions about rationality and markets that are embodied in many modern theoretical models, my own included,” he still find them useful “as a way of thinking through some issues carefully.”

When it comes to methodology and assumptions, Krugman obviously has a lot in common with the kind of model-building he otherwise criticizes. And as Rosenberg rightly notices:

When he accepts maximizing and equilibrium as the (only?) way useful economics is done Krugman makes a concession so great it threatens to undercut the rest of his arguments against New Classical economics.

Is ‘modern’ macroeconomics for real?

12 January, 2019 at 10:59 | Posted in Economics | 1 Comment

861cf344575acd50ed67b35d88615f2318610d8148e8c471ad10ca0132cda91eEmpirically, far from isolating a microeconomic core, real-business-cycle models, as with other representative-agent models, use macroeconomic aggregates for their testing and estimation. Thus, to the degree that such models are successful in explaining empirical phenomena, they point to the ontological centrality of macroeconomic and not to microeconomic entities … At the empirical level, even the new classical representative-agent models are fundamentally macroeconomic in content …

The nature of microeconomics and macroeconomics — as they are currently practised​ — undermines the prospects for a reduction of macroeconomics to microeconomics. Both microeconomics and macroeconomics must refer to irreducible macroeconomic entities.

Kevin Hoover

Kevin Hoover has been writing on microfoundations for more than 25 years, and is beyond any doubts the one economist/econometrician/methodologist who has thought most on the issue. It’s always interesting to compare his qualified and methodologically founded assessment on the representative-agent-rational-expectations microfoundationalist program with the more or less apologetic views of freshwater economists like Robert Lucas:

hoovGiven what we know about representative-agent models, there is not the slightest reason for us to think that the conditions under which they should work are fulfilled. The claim that representative-agent models provide microfoundation​s succeeds only when we steadfastly avoid the fact that representative-agent models are just as aggregative as old-fashioned Keynesian macroeconometric models. They do not solve the problem of aggregation; rather they assume that it can be ignored. While they appear to use the mathematics of macroeconomics​, the subjects to which they apply that microeconomics are aggregates that do not belong to any agent. There is no agent who maximizes a utility function that represents the whole economy subject to a budget constraint that takes GDP as its limiting quantity. This is the simulacrum of microeconomics, not the genuine article …

[W]e should conclude that what happens to the microeconomy is relevant to the macroeconomy but that macroeconomics has its own modes of analysis … [I]t is almost certain that macroeconomics cannot be euthanized or eliminated. It shall remain necessary for the serious economist to switch back and forth between microeconomics and a relatively autonomous macroeconomics depending upon the problem in hand.

Instead of just methodologically sleepwalking into their models, modern followers of the Lucasian microfoundational program ought to do some reflection and at least try to come up with a sound methodological justification for their position. Just looking the other way won’t do. Writes Hoover:

garciaThe representative-­agent program elevates the claims of microeconomics in some version or other to the utmost importance, while at the same time not acknowledging that the very microeconomic theory it privileges undermines, in the guise of the Sonnenschein-­Debreu­-Mantel theorem, the likelihood that the utility function of the representative agent will be any direct analogue of a plausible utility function for an individual agent … The new classicals treat [the difficulties posed by aggregation] as a non-issue, showing no appreciation​ of the theoretical work on aggregation and apparently unaware that earlier uses of the representative-agent model had achieved consistencywith​h theory only at the price of empirical relevance.

Where ‘New Keynesian’ and New Classical economists think that they can rigorously deduce the aggregate effects of (representative) actors with their reductionist microfoundational methodology, they — as argued in my On the use and misuse of theories and models in economics — have to put a blind eye on the emergent properties that characterize all open social and economic systems. The interaction between animal spirits, trust, confidence, institutions, etc., cannot be deduced or reduced to a question answerable on the individual level. Macroeconomic structures and phenomena have to be analyzed also on their own terms.

What is missing in Keynes’ General Theory

10 January, 2019 at 11:55 | Posted in Economics | 1 Comment

The cyclical succession of system states is not always clearly presented in The General Theory. In fact there are two distinct views of the business cycle, one a moderate cycle which can perhaps be identified with a dampened accelerator-multiplier cycle and the second a vigorous ‘boom and bust’ cycle … The business cycle in chapter 18 does not exhibit booms or crises …

jmkIn chapter 12 and 22, in the rebuttal to Viner, and in remarks throughout The General Theory, a vigorous cycle, which does have booms and crises, is described. However, nowhere in The General Theory or in Keynes’s few post-General Theory articles explicating his new theory are the boom and the crisis adequately defined or explained. The financial developments during a boom that makes a crisis likely, if not inevitable, are hinted at but not thoroughly examined. This is the logical hole, the missing link, in The General Theory as it was left by Keynes in 1937 after his rebuttal to Viner … In order to appreciate the full potential of The General Theory as a guide to interpretation and understanding of moderrn capitalism, we must fill out what Keynes discussed in a fragmentary and casual manner.

Mediernas ensidiga ekonomirapportering

9 January, 2019 at 08:25 | Posted in Economics | 3 Comments

När svenska medier vill veta något om ekonomi frågar de Arturo Arques.Han är privatekonom på en storbank och när tidningen Flamman i förra veckan (4 jan) granskade vilka ekonomer som citeras i 100 artiklar i svensk press är han kårens mest pratsamma stjärna …

moneySex av tio intervjuade ekonomer kommer från näringslivet, framför allt från arbetsgivarorganisationer, banker och försäkringsbolag. Det är tiofalt fler än från facken och deras närstående organisationer, till exempel tankesmedjor.

En sådan dominans formar naturligtvis själva idén om det sunda förnuftet, om vad som är möjligt, önskvärt och naturligt – och vad som är udda och galet. Vi får också, som nationalekonomen Lars Pålsson Syll säger till Flamman, en falsk bild av att ekonomkåren är enig och i förlängningen att ekonomi är ett nästan naturvetenskapligt ämne, vars grundsatser inte kan ifrågasättas.

Visst, ekonomerna kan säkert vara klädsamt oeniga i detaljer, men det är knappast någon djärv gissning att inte en enda av dem propagerar för fyra dagars arbetsvecka, nolltillväxt, nationalisering av storbankerna eller konfiskatoriska förmögenhetsskatter.

Det är liksom inte det de får betalt för.

Petter Larsson/Aftonbladet

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