Ergodicity and stationarity in random processes (super wonkish)

30 April, 2013 at 18:25 | Posted in Statistics & Econometrics | 5 Comments



Deductive models leading us astray

30 April, 2013 at 09:39 | Posted in Economics, Theory of Science & Methodology | 2 Comments

Oxford professor John Kay has a very interesting article on why economists have tended to go astray in their – as my old mentor Erik Dahmén used to say – tool sheds:

grand-theft-autoConsistency and rigour are features of a deductive approach, which draws conclusions from a group of axioms – and whose empirical relevance depends entirely on the universal validity of the axioms. The only descriptions that fully meet the requirements of consistency and rigour are completely artificial worlds, such as the “plug-and-play” environments of DSGE – or the Grand Theft Auto computer game.

For many people, deductive reasoning is the mark of science: induction – in which the argument is derived from the subject matter – is the characteristic method of history or literary criticism. But this is an artificial, exaggerated distinction. Scientific progress – not just in applied subjects such as engineering and medicine but also in more theoretical subjects including physics – is frequently the result of observation that something does work, which runs far ahead of any understanding of why it works.

Not within the economics profession. There, deductive reasoning based on logical inference from a specific set of a priori deductions is “exactly the right way to do things”. What is absurd is not the use of the deductive method but the claim to exclusivity made for it. This debate is not simply about mathematics versus poetry. Deductive reasoning necessarily draws on mathematics and formal logic: inductive reasoning, based on experience and above all careful observation, will often make use of statistics and mathematics.

Economics is not a technique in search of problems but a set of problems in need of solution. Such problems are varied and the solutions will inevitably be eclectic. Such pragmatic thinking requires not just deductive logic but an understanding of the processes of belief formation, of anthropology, psychology and organisational behaviour, and meticulous observation of what people, businesses and governments do.

The belief that models are not just useful tools but are capable of yielding comprehensive and universal descriptions of the world blinded proponents to realities that had been staring them in the face. That blindness made a big contribution to our present crisis, and conditions our confused responses to it. Economists – in government agencies as well as universities – were obsessively playing Grand Theft Auto while the world around them was falling apart.

The article is essential reading for all those who want to understand why mainstream – neoclassical – economists actively have contributed to causing todays’s economic crisis rather than to solving it.

Perhaps this becomes less perplexing to grasp when considering what one of its main proponents today – Robert Lucas – maintained already in 2003:

My thesis in this lecture is that macroeconomics in this original sense has succeeded: its central problem of depression-prevention has been solved, for all practical purposes, and has in fact been solved for many decades.

And this comes from an economist who has built his whole career on the assumption that people are hyper rational “robot imitations” with rational expectations and next to perfect ability to process information. Mirabile dictu!

The kings and queens around my room with their quiet dirty looks

28 April, 2013 at 11:45 | Posted in Varia | Leave a comment


Money is … uhmm … ehhh …

27 April, 2013 at 15:35 | Posted in Economics | Leave a comment

Macro 101

27 April, 2013 at 15:01 | Posted in Economics | Leave a comment

fallacy1. The economy isn’t like an individual family that earns a certain amount and spends some other amount, with no relationship between the two. My spending is your income and your spending is my income. If we both slash spending, both of our incomes fall.

2. We are now in a situation in which many people have cut spending, either because they chose to or because their creditors forced them to, while relatively few people are willing to spend more. The result is depressed incomes and a depressed economy, with millions of willing workers unable to find jobs.

3. Things aren’t always this way, but when they are, the government is not in competition with the private sector. Government purchases don’t use resources that would otherwise be producing private goods, they put unemployed resources to work. Government borrowing doesn’t crowd out private borrowing, it puts idle funds to work. As a result, now is a time when the government should be spending more, not less. If we ignore this insight and cut government spending instead, the economy will shrink and unemployment will rise. In fact, even private spending will shrink, because of falling incomes.

4. This view of our problems has made correct predictions over the past four years, while alternative views have gotten it all wrong. Budget deficits haven’t led to soaring interest rates (and the Fed’s “money-printing” hasn’t led to inflation); austerity policies have greatly deepened economic slumps almost everywhere they have been tried.

5. Yes, the government must pay its bills in the long run. But spending cuts and/or tax increases should wait until the economy is no longer depressed, and the private sector is willing to spend enough to produce full employment.

Paul Krugman

What is money?

27 April, 2013 at 14:26 | Posted in Economics | Leave a comment


(h/t Jan Milch)

Rogoff-Reinhart-skandalen och sifferexercisens gränser

27 April, 2013 at 12:42 | Posted in Varia | 1 Comment

All ekonomi är i slutändan summan av mänskliga handlingar, vars logik sällan ryms i ett Excelark …

liesInte ens den matematiskt mest fulländade ekvation kan användas som ursäkt för att strunta i det viktigaste: en manuell rimlighetsbedömning. Om bilens GPS ger instruktioner om högersväng utför ett stup betyder det inte nödvändigtvis att det är en bra idé. Förklaringen till att den ortodoxa siffertron vinner allt mer terräng kanske snarare ligger i att det är en bekväm metod att få sin vilja igenom. Det är nämligen med ekonomisk statistik som med så mycket annat: vi väljer att se det vi vill se.

Andreas Cervenka, SvD Näringsliv

Rolling In The Deep

27 April, 2013 at 11:42 | Posted in Varia | Leave a comment


Axel Leijonhufvud interviewing Hayek (!)

26 April, 2013 at 17:31 | Posted in Economics, Politics & Society | Leave a comment

(h/t Lord Keynes)

Tillväxt och miljö

26 April, 2013 at 16:01 | Posted in Varia | Leave a comment

Yours truly var igår inbjuden till en debatt på Handelshögskolan i Göteborg. Temat var tillväxt och miljö. Jag vet inte om jag lyckades övertyga alla som lyssnade om att det faktiskt är möjligt att leva bra och fullvärdiga liv utan att överkonsumera.
De som till äventyrs inte övertygades av mina åberopade teoretiska inspirationskällor – Soddy, Georgeescu-Roegen och Boulding m fl- kanske istället kan få sig åtminstone en tankeväckare av Nina Hedenius underbara – och via SvT:s Öppet arkiv numera nedladdningsbara – dokumentärfilm Gubben i stugan – som handlar om den pensionerade skogsarbetaren Ragnars liv i Dalarnas finnskogar.

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