Thursday, October 29, 2009

Hey, it's nearly Christmastime again!

Look out! It's a book by Joel Waldfogel based on the deadweight loss of Christmas! I have made my point on the topic already, so I'm going to do my best to hide from any and all reviews of the new book.

Did I mention it's called "Scroogenomics"?

Leech the economy

Anatole Kaletsky's evisceration of "old economics" in the London Times may be consistent with the general backlash during the current recession, but it's half-baked.

Today’s academic approach prevented economists from thinking about a world that is, by its very nature, unpredictable and inconsistent... others may revive the literary and anecdotal traditions of the great economists of the past... Smith and Hayek produced no real mathematical models. Their eloquent writing lacked the “analytical rigour” demanded by modern economics. And none of them ever produced an econometric forecast.

To wish simultaneously for a return to an "anecdotal tradition" and for theories to be "tested against reality" is perverse. The economy is indeed a complex system, and to draw correct conclusions on the relationships in a complex system requires more than anecdote. As epidemiology is to medicine, so econometrics is to economics; a
patient's recovery after leeching does not prove leeching effective, and folk inference in economics would be just as counterproductive, in its own way. The "analytical rigour" so disdained by Mr. Kaletsky represents the struggle to understand and draw inference from the very real complexity that to rely on anecdote risks ignoring.

The first idea, known as “rational expectations”, maintained that capitalist economies with competitive labour markets do not need stabilising by governments.

The second idea — “efficient markets” — asserted that competitive finance always allocates resources in the most efficient way, reflecting all the best available information and forecasts about the future.

The specific "theories" attacked by Mr. Kaletsky are also grossly misrepresented. Hell, the concept of a theory is being misrepresented. An economic theory is an if-then statement, and this is not a matter of mathematics, which is after all just a language like any other. No theory, no matter how it is expressed, can ever do more than suggest the outcome that would pertain under a given set of conditions. No theory, then, can "[maintain] that capitalist economies... do not need stabilizing by governments", or "[assert] that competitive finance always allocates resources in the most efficient way". To attack the assumptions underlying these theories is good and rigorous; to either attack the value of their existence is to distort the purpose of academic inquiry. It is precisely because
theories are if-then that any single conclusion can be given an 'if' and be co-opted and championed by the politically powerful of the moment, but the "assertions" come always from the interpreter, not from the theorem.

Literary and cross-disciplinary approaches to economics can have great value in conveying economic ideas and in complementing other forms of research. What would be unacceptable, however, would be the abandonment of valuable tools to help us to understand the way things are. Perhaps attacking economists makes us feel better, but this is like blaming the shipbuilder, engineer or mathematician for a drunk captain's crash.

And finally, because that felt a bit too serious, I must mention these:

Today’s academic economics reverses this process: if models disagree with reality, it is reality that economists want to change.

Policymakers who turned to academic economists for guidance in last year’s crisis were told in effect: "The situation you are dealing with is impossible: our theories prove that it simply cannot exist."

This is garbage.

Thursday, April 30, 2009

It's called "the ivory tower"

Here's a thoughtful antidote to "boo economists!" by Barry Eichengreen at The National Interest. Perhaps the most forceful point is this:

What got us into this mess, in other words, were not the limits of scholarly imagination. It was not the failure or inability of economists to model conflicts of interest, incentives to take excessive risk and information problems that can give rise to bubbles, panics and crises. It was not that economists failed to recognize the role of social and psychological factors in decision making or that they lacked the tools needed to draw out the implications. In fact, these observations and others had been imaginatively elaborated by contributors to the literatures on agency theory, information economics and behavioral finance. Rather, the problem was a partial and blinkered reading of that literature. The consumers of economic theory, not surprisingly, tended to pick and choose those elements of that rich literature that best supported their self-serving actions. Equally reprehensibly, the producers of that theory, benefiting in ways both pecuniary and psychic, showed disturbingly little tendency to object. It is in this light that we must understand how it was that the vast majority of the economics profession remained so blissfully silent and indeed unaware of the risk of financial disaster.

Eichengreen notes that business schools, for example, are part of the production line of financial labor and ideas and so have no inventive to rock the boat; however, he also directs a lot of fire at academic economists for being part of the stitch-up. I accept that the author surely knows better than me the "pecuniary and psychic" benefits to academics from the use of their work, but a counter-hypothesis would be ignorance rather than malice, a sin of omission, not commission. How many in economics departments know what's going on in industry - or even business schools? Is it enough to claim a quorum of the profession?

There's probably analog to the hard sciences here. Newspaper science (cf. Bad Science, for example) is to natural science research as financial industry models are to economics research, or something like that. Imagine a house full of economists (reality show idea?) - every so often one wanders out to hand some obscure technical document to someone from the outside world, and something inevitably gets lost in translation. 

Wednesday, April 22, 2009

More navel-gazing

Since there are now, I estimate, more articles on the economics profession's predictions/responses to the recession than there are atoms in the known universe, replying to them all would presumably take a very long time. One example will probably suffice. 

In the Financial Times yesterday, John Kay talks about "How economics lost sight of real world". 

The past two years have not enhanced the reputation of economists. Mostly they failed to point out fundamental weaknesses of financial markets and did not foresee the crisis, and now they disagree on appropriate policies and on the likely future course of events.

As I have (almost) argued before, this is - for better or for worse - not in the job description of the vast majority of academic economists. It is precisely like attacking a physics professor because there was a blackout last night. More importantly:

Economists, like physicists, have been searching for a theory of everything. If there were to be such an economic theory, there is really only one candidate, based on extreme rationality and market efficiency.... a few deranged practitioners of the project believe that their theory really does account for all human behaviour, and that concepts such as goodness, beauty and truth are sloppy sociological constructs.

I have addressed the "economists don't feel feelings" argument before. And, by the way, I guess you can color me deranged. Economics is a theory of everything! 

First: the assumption of "rationality" that is central to economic theory is a modeling assumption and makes no restriction on behavior whatsoever. The auxiliary assumptions of what people care about - the things that they "rationally" try to achieve with their limited resources - are restrictive. Second: "market efficiency" is neither a theory or a modeling assumption. It is either a metric (one of many) by which we can evaluate outcomes (i.e. is this "efficient"?) or a result of an economic theory, which, like all economic theories, will probably require many assumptions. 

I would agree with the proposition that it is wrong to assume that markets are "efficient" (and what does that even mean?). Economists do not make such an assumption. I would agree with the proposition that it is wrong to assume that people care only about their own material wellbeing. Economists do not make such an assumption.

Academic economists did not predict this recession because that is not what academic economists are "supposed" to do with their time. 

Learning from your mistakes

The big policy lesson from our current recession is: save money in good times to see you through the bad. Obvious? Apparently not, especially in Britain, where the government spent the unprecendentedly long expansion period from the late 90s to 2007 running deficits. But it's good to know that we can learn from our mistakes, right? 

But [Alistair Darling] made clear his plans depended on a rapid economic bounce-back - with a forecast of 1.25% growth next year rising to 3.5% in 2011. [link]

The IMF World Economic Outlook (WEO) report predicts the UK economy will shrink by 4.1pc in 2009, with the downturn expected to continue into next year when the economy will fall by 0.4pc. [link]

This is unacceptable. After years of squandering prosperity by running deficits in boom years, now the government proposes to dig even deeper. 

My university, Brown, is cutting staff right now. By anecdote, it is far from alone in the higher education world in doing so. Why is it that a bad year means the operating budget is slashed? Why was the financial plan based on an assumption of constant, unlimited growth in the endowment (i.e. a constant, unlimited rise in stock prices)? Why were national governments operating under the same assumptions? 

Thursday, February 26, 2009

Experimental philosophy, experimental economics

Interesting article at Prospect Magazine called Philosophy's Great Experiment, about the rise of 'experimental philosophy'. Doubly interesting to me, because it could equally well be talking about experimental economics, albeit a few years too late. Or about "neuroeconomics"; the philosophers in the article are using fMRI machines "to look for patterns of neuronal activity when subjects are presented with philosophical problems", just like the researcher who does the same for resource allocation - economics - problems. But here's the rub:

Some philosophers quietly dismiss the movement as a cynical step by researchers to appear cutting edge and to tap into scientists’ funding.

Indeed, it's easy to feel this way about the kind of experiments in which economists step on psychologists' toes. The drive toward empiricism in philosophy that the article talks about seems to be symptomatic of social sciences' and humanities' desire to be taken "seriously" as science.

And as we know, that means we need something falsifiable or verifiable. "There is no article in Prospect Magazine called Philosophy's Great Experiment" is falsifiable, because I can find such an article and falsify the statement. "There is at least one article in Prospect Magazine called Philosophy's Great Experiment" is verifiable, because I can find such an article and verify the statement. 

In experimental economics, often it seems (at least to this observer) that we're replicating, or at least mirroring, psychology experiments. Unfortunately, the economics experiment is much less likely to be "scientific", not because of the method or the issue at hand, but because of the specific question. This is precisely what Lawrence Boland discusses in the paper "On the futility of criticizing the neoclassical maximization hypothesis" (pdf), which I read as a welcome withering put-down to all of those who claim to "disprove rationality", etc etc. He says:

Properly stated, the neoclassical premise is: ‘For all decision makers there is something they maximize’... The person who assumed the premise is true can respond: ‘You claim you have found a consumer who is not a maximizer but how do you know there is not something which he is maximizing?’

For experimental economists and experimental philosophers alike, the challenge is to pose a scientific question; without that, no method will save us. "Are people ethical?", for example, is equally a dead end as "are people rational?".