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.

Close to the ground

Hey, it's John McCain time again! The Free Exchange blog has this (under the nifty headline 'Tsk-onomics'), on the familiar topic of McCain's support for the gas tax 'holiday'. Congress doesn't like it, economists don't like it, so far so familiar.

Apparently McCain's getting slammed for being rubbish at answering questions on this, and other, policies he's advocating, but let's leave that to the analysts. There's a fun exchange quoted from a George Stephanopoulos chat with McCain:

STEPHANOPOULOS: Not a single economist in the country said it’d work.

MCCAIN: Yes. And there’s no economist in the country that knows very well the low-income American who drives the furthest, in the oldest automobile, that sometimes can’t even afford to go to work.

I think it's neat that presidential candidates get chips by opposing economists, and I don't mean that as an offended economist; I think it's interesting. Anyway, is there any merit in that particular McCain quotation? Or, to paraphrase: is economics too far from the ground? Is it too esoteric to properly understand the actual, real implications of its preditions, its recommendations?

The classic case, I think, might be the globalization debate, the protectionism debate: typical economist's position might be 'trade good because it allows specialization based on comparative advantage, cheap stuff, more to go around etc'; the counter-argument could run 'trade bad, erodes localism which we like, hurts those people whose livelihood depends on those things that their country will stop producing when trade makes it cheaper to get those things from other countries'.

Now, sure, the response to the latter is usually 'yes, yes, we know some people lose out, compensate the losers', but is that particularly constructive? Are we blind to the real, tangible content of the disagreement with the 'economist's answers'? Do we splutter and get indignant with John McCain because he had bad policies, or because we don't really get the argument?

When we say 'your gas tax holiday plan sucks, aha!', we lose friends and alienate people; could we actually make economists a little cuddlier and meet McCain halfway? How can we deal with the problems he's referring to, that people feel like they're struggling to get by? We don't deal with it by ridiculing, that's for sure. There's no need to compromise if you think a gas tax holiday isn't right, so by all means make that case, but every time an economist is painted into a corner as an enemy of the prosperity of the common man, we must argue our way out double-quick, as a matter of principle and credibility.

Dinner party advice for the economist

From The Economist's Free Exchange blog, comes some dinner party advice, based on Justin Wolfers:

JUSTIN WOLFERS discusses a common problem for the economist bon vivant—people are always asking you what's going to happen to such and such economic variable. Will the economy go into recession? Will the Federal Reserve raise interest rates? Should I sell my shares in Bear Stearns?

Very true. It's no fun at all to have to admit to being an economist.

On the Venn diagram of 'what people think of when they meet someone who introduces themselves as an economist', macroeconomic stuff (inflation, unemployment) and finance (stocks, commodities, assets) are huge whopping great circles, much bigger than they are on the 'what economists do' diagram. Hence the point of this site, I suppose.

Anyway, here's some advice:

Henceforth, when asked about oil prices, simply throw out some jargon, use phrases like "short-run volatility", and then suggest that the price in three months' time, or indeed a year, will be the same as it is today.

I love it.

Economists talk weird

I was going to rant a bit about "Lessons in Love, by Way of Economics" by Ben Stein from the New York Times, but, and I didn't even think this was possible, the whole thing is too ridiculous to justify it. Suffice to say it's more bad PR for the poor econ set.

One of my least favorite things about economists is that we often seem more prone to talking about normal stuff in economics-speak. You'd like an example?

In every long-term romantic situation, returns are greater when there is a monopoly.

Good grief. I mean, who is reading a bunch of aphorisms about 'love' translated into economics jargon and thinking 'awesome article'? Plus, as an added irritant, half the dodgy analogies are to finance, not economics, viz "[t]he returns on your investment should at least equal the cost of the investment" etc etc.

Who knows, maybe there could be something interesting under that title. What I hoped might crop up in an article with such a title might be something about the things people want, the monetizing of economics versus the rich motivations of life. From the tail end of the article:

Ben Franklin summed it up well. In times of stress, the three best things to have are an old dog, an old wife and ready money.

OK. It's the old "no-one ever died wishing they'd spent more time at the office" bit. Shouldn't that apply to economists too? Then why are economists so keen to spend all their time at the office by talking about normal stuff in economics jargon? That's tiresome, not fun.

What economists do: the one model we use

Economics is jargon-heavy, like, well, everything. Economists, I can attest, are especially fond of that academic disease of using their jargon in everyday conversation, a kind of subconscious economic imperialism. Nevertheless, there's a difference between specialist knowledge (with its public face, jargon) and the concepts on which a body of knowledge is built.

How could we distill economics to its base? This is a slightly different goal than defining the principles of economics; here we want to identify the actual applicable results that derive from the principles and recur again and again in the whole discipline. As a first pass at this problem, let's look at the model we use in economics. That's model, singular.

Modern economics is built on the formalized statement of the definition of the subject: some entity has objectives, and limited resources with which to achieve them. These become the objective function and the constraints. Now the entity could be anything: a firm, a person, a government, a group of people.

The objective function might be expressed in math, but it doesn't have to be. It reflects, obviously, the objectives of the entity, and these could be anything, but will typically have to be a simplified version of what an entity really wants or needs. This is one place where the abstraction from reality might have to be made, although we can imagine, as a thought experiment, the omniscient modeler who is not subject to this particular problem.

The constraints can, again, be put into math but doesn't have to be. It is the expression of scarcity; constraints can reflect anything that poses a challenge to our entity's achieving its goal. The abstraction is often necessary here, too: time, money, social convention, technology are just some of the possible constraints.

Now this is really a very simple idea, but all economics uses this as its base. We are concerned with the allocation of scarce resources in the quest to satisfy objectives, and this is the model of that. The math angle comes in to make this model give tangible and quantifiable results; we could make arguments without the math, but using it often helps to make things clear. The challenge for the modeler is to write the model cleverly, making simplifications enough to make the problem understandable, but not too many to make it irrelevant.

Theoretical economists are explicitly writing this model, over and over, and the illustrative economic models we present in teaching students use this model exclusively. Empirical economists use it too, not just writing it down, but in subtle ways: perhaps the empiricist can identify a precise moment or situation in which the constraints on a particular entity's problem changed, offering them a useful opportunity to see how choices change in the face of the discrete change in conditions.

This model gives rise to the marginalist result. It says that our entity will allocate resources to a particular use while the benefit of doing so exceeds the cost of doing so, and that the point at which the entity stops will be characterized by the balance of cost and benefit at that particular point. If the decision was changed slightly in either direction, the results would be less satisfying, either because the cost would exceed the benefit, or because the benefit would exceed the cost. That might sound complicated, but it is a familiar idea from everyday life.

In the jargon, the result is that marginal benefit equals marginal cost in the solution to this model of an entity facing a resource allocation model. That simply means that from the "solution", there is no change that would be a better result for the objective function. Not to say that the solution is a perfect prediction or description; the solution is to the model, not the actual problem faced by the entity. Perhaps the loaded meaning of the word solution is a hindrance here. Much debate has been staged over the extent of predictive or descriptive accuracy of this economic model.

Where it gets a bit complicated is at the point where we're unsatisfied with the objectives or constraints we are using in our models. Benefit and cost are pretty easy to think about when our abstraction acknowledges only money, for example, but what if my entity's objective function included the wellbeing of others, the environment, the amount of time spent in the sun, the quality of life? These assumptions are not just more difficult to incorporate, they are more difficult to interpret.

Where does all this fit in with the themes I've touched on before? The debate about rationality, economic man and realism informs directly the objective function. For example, the behavioral school could be characterized as seeking to come up with a more realistic, tractable objective function. The economics-as-money fallacy crops up in both the objective and constraints, yet how we denominate these things doesn't change the model one bit. The debate about math in economics informs the language in which the model is presented; non-mathematical economists still use the model, even if they don't write all these components down as mathematical relationships.

This is the model of economics. Two examples to show what's going on.

First: how would a subsidy on the wage of low-income workers, such as the Earned Income Tax Credit, affect the number of people who work and how much they work? The common treatment of this problem in basic economics is to imagine a person who has a desire for money and for time, and to illustrate the wage subsidy as affecting the constraint, in this case the rate at which our person can earn money by giving up their time to work. We can then ask how this change in the constraint affects the hypothetical best choice of our simple person, and even ask how the person's relative desire for time and money affect this answer.

Theorists can try to answer this question by investigating the model itself; empiricists might look to the data to try to identify the change in actual choices observed when the subsidy is introduced. [Aside: as it turns out, weird things happen with the EITC during the income range when it's gradually phased out.]

Second: how would a person choose to react to another person they perceive to be unfair? Our person might have an objective function that includes preference for money and fairness, and their constraint could include the social norms for fairness as well as their money budget. This example is well-studied in experimental economics, where our person can decide to sacrifice some common good in order to punish a person who was greedy.

No matter what field of economics one works in, this is the one model most dominant in all of the work. It is, of course, very flexible (in fact, infinitely flexible, as I argued before), and I have stated it in the most general terms. Nevertheless, when economists argue, it is worth remembering that we all play the same game. It might just be the language, but it is a language that can seem daunting and restrictive to outsiders or students. I don't believe that is the case: the beauty of this most fundamental model is its simplicity and its malleability. To distill economics into its essence, this is the place to start.

What economists do: theory versus empirics

Down to dirty work today, as I make the bold claim to start talking about the guts of the economics profession. What are we up to? The first distinction in economics research methodology is 'theory' versus 'empirics'. Specialization has gotten to us in a big way here, in that theorists and empiricists don't really associate at all.

So what's what? Both methods are trying to attack similar questions - what happens if this changes, how do I achieve this, what is the relationship between these things - but use very different standards of proof. A theoretical 'proof' is to create a simplified model of reality to speculate on how the things might be related, while empiricists dig into big datasets to try to find the real-world relationship, the common problem being that things are pretty complicated. When economists talk about "applied economics", they are using a label for the practice of statistical analysis of data in empirical economics research, so in some sense "applied" is not really an informative word here.

When we actually want to answer questions, say for policy analysis or just because we care, it is obviously smart to draw on diversity and explore the theoretical reasoning behind the relationship you're interested in as well as whatever suggestive real-world evidence exists. Being that this isn't what economic research papers do, this isn't what economists do, though: we all do either one or the other whenever we write a research paper. Every economist is, first and foremost, a theorist or an empiricist (or both, but you see what I mean - they are distinct concepts at all moments).

The problem for empiricists is, in a way, harder than for theorists, because finding meaningful relationships in real data is surprisingly difficult, and assuming something away is a much more technical proposition when you have to kill it in your actual data rather than just in your abstraction. For example, if I see that the airport built a new terminal and that house prices went down, I can certainly argue that one caused the other, but actually proving it is a very different proposition. Econometrics is the branch of economics that tries to develop methods to analyze data where it's difficult to infer causality. Of course, this problem is common to all statistical analysis, not just economics, and it is surely true that really strong evidence is revealed without fancy techniques.

A lot of economists do "applied economics". Now this is going to be mostly just an anecdotal claim, but it's certainly plausible to argue that the things that made economists decide to become economists seldom include a burning desire to trawl through huge datasets and run a bunch of regressions; the questions that can be answered in this way are interesting, sure, but the work itself is not a lot of fun. On top of that, despite the positivist teaching of economics, the proportion of time spent on the empirical methods is very, very small compared to the proportion of economics research that is empirical. Not that this is a bad thing: there isn't a huge amount you can say about empirical methods before you're actually in a position to use them (and again: not that much fun), but it might be presenting a drastically skewed picture of what it means to be an economist.

There's actually a bit of a rift within empirical economics about the role of theory, which is a different matter entirely - I'll try to paraphrase to the best of my ability. That rift concerns the seed of the empirical test being done - should it be explicitly associated with a theoretical model of the relationship you're looking for in the data (that's 'structuralist'), or should the data be allowed to speak for itself and leave models out of it ('reduced form')? Now, the funny thing is that, as we know, it's possible to write down a self-contained and consistent theoretical model that proves any relationship you want; the value of the model depends entirely on how you judge the value of its own little world. Thus, employing theory as some kind of dual proof while doing empirical work is actually redundant; it can offer some clarification of what you think might be driving the relationship you've found in the data, but it's not especially helpful to say "hey, I found this empirical evidence - and look, the model says the same thing!".

Which, again, is different from the idea of puzzling out a theoretical idea then trying to find evidence to see if it's true or not. This kind of thing is actually not incredibly popular, perhaps because of the vastly different worlds theorists and empiricists orbit in - different methods, different seminars, different journals. The paradox is thus that very little empirical economics research actually tests theoretical economic hypotheses. Does each approach lend itself to different questions, never the two to meet, or is it in fact just that we don't like following on each others' coattails?

Back to the big point. Let's say I'm a research economist and I'm thinking of a question like this: "would a national health service be good for the United States?" What I will not end up doing is writing an answer to that question, drawing on the arguments and evidence from a variety of sources. The economist's role in answering such questions depends on which flavor of economist he is. The theorist might end up asking "how would it change the problem for an individual if they were faced with a national health service rather than the current system?" She might create a little model of a person facing choices between spending their money on health care or on other things, who goes on to interact with an insurance company in one instance or the new health service in the other, and figure out how that person's choices might plausibly change.

The empiricist might end up asking something like "how does the size of a deductible affect people's health care spending?", since this might tell us something about the zero-deductible world of national health care, or "how do wait times affect health outcomes?". Note that to answer the original question - should the US switch systems - using any kind of data, or indeed any kind of theoretical model, is staggeringly complicated and difficult.

Neither type of economist actually writes about the answer to the big question in their academic research. Instead, they go to the questions that their method might be able to answer, making just one brushstroke on the painting of the argument, and for theorists and empiricists, those questions are very seldom the same.