rational expectations

How following the crowd can doom us all

pnrj heuristics and biases , , , , , , , , , , , , , , , , , , , , , , , ,

JDN 2457110 EDT 21:30

Humans are nothing if not social animals. We like to follow the crowd, do what everyone else is doing—and many of us will continue to do so even if our own behavior doesn’t make sense to us. There is a very famous experiment in cognitive science that demonstrates this vividly.

People are given a very simple task to perform several times: We show you line X and lines A, B, and C. Now tell us which of A, B or C is the same length as X. Couldn’t be easier, right? But there’s a trick: seven other people are in the same room performing the same experiment, and they all say that B is the same length as X, even though you can clearly see that A is the correct answer. Do you stick with what you know, or say what everyone else is saying? Typically, you say what everyone else is saying. Over 18 trials, 75% of people followed the crowd at least once, and some people followed the crowd every single time. Some people even began to doubt their own perception, wondering if B really was the right answer—there are four lights, anyone?

Given that our behavior can be distorted by others in such simple and obvious tasks, it should be no surprise that it can be distorted even more in complex and ambiguous tasks—like those involved in finance. If everyone is buying up Beanie Babies or Tweeter stock, maybe you should too, right? Can all those people be wrong?

In fact, matters are even worse with the stock market, because it is in a sense rational to buy into a bubble if you know that other people will as well. As long as you aren’t the last to buy in, you can make a lot of money that way. In speculation, you try to predict the way that other people will cause prices to move and base your decisions around that—but then everyone else is doing the same thing. By Keynes called it a “beauty contest”; apparently in his day it was common to have contests for picking the most beautiful photo—but how is beauty assessed? By how many people pick it! So you actually don’t want to choose the one you think is most beautiful, you want to choose the one you think most people will think is the most beautiful—or the one you think most people will think most people will think….

Our herd behavior probably made a lot more sense when we evolved it millennia ago; when most of your threats are external and human beings don’t have that much influence over our environment, the majority opinion is quite likely to be right, and can often given you an answer much faster than you could figure it out on your own. (If everyone else thinks a lion is hiding in the bushes, there’s probably a lion hiding in the bushes—and if there is, the last thing you want is to be the only one who didn’t run.) The problem arises when this tendency to follow the ground feeds back on itself, and our behavior becomes driven not by the external reality but by an attempt to predict each other’s predictions of each other’s predictions. Yet this is exactly how financial markets are structured.

With this in mind, the surprise is not why markets are unstable—the surprise is why markets are ever stable. I think the main reason markets ever manage price stability is actually something most economists think of as a failure of markets: Price rigidity and so-called “menu costs“. If it’s costly to change your price, you won’t be constantly trying to adjust it to the mood of the hour—or the minute, or the microsecond—but instead trying to tie it to the fundamental value of what you’re selling so that the price will continue to be close for a long time ahead. You may get shortages in times of high demand and gluts in times of low demand, but as long as those two things roughly balance out you’ll leave the price where it is. But if you can instantly and costlessly change the price however you want, you can raise it when people seem particularly interested in buying and lower it when they don’t, and then people can start trying to buy when your price is low and sell when it is high. If people were completely rational and had perfect information, this arbitrage would stabilize prices—but since they’re not, arbitrage attempts can over- or under-compensate, and thus result in cyclical or even chaotic changes in prices.

Our herd behavior then makes this worse, as more people buying leads to, well, more people buying, and more people selling leads to more people selling. If there were no other causes of behavior, the result would be prices that explode outward exponentially; but even with other forces trying to counteract them, prices can move suddenly and unpredictably.

If most traders are irrational or under-informed while a handful are rational and well-informed, the latter can exploit the former for enormous amounts of money; this fact is often used to argue that irrational or under-informed traders will simply drop out, but it should only take you a few moments of thought to see why that isn’t necessarily true. The incentives isn’t just to be well-informed but also to keep others from being well-informed. If everyone were rational and had perfect information, stock trading would be the most boring job in the world, because the prices would never change except perhaps to grow with the growth rate of the overall economy. Wall Street therefore has every incentive in the world not to let that happen. And now perhaps you can see why they are so opposed to regulations that would require them to improve transparency or slow down market changes. Without the ability to deceive people about the real value of assets or trigger irrational bouts of mass buying or selling, Wall Street would make little or no money at all. Not only are markets inherently unstable by themselves, in addition we have extremely powerful individuals and institutions who are driven to ensure that this instability is never corrected.

This is why as our markets have become ever more streamlined and interconnected, instead of becoming more efficient as expected, they have actually become more unstable. They were never stable—and the gold standard made that instability worse—but despite monetary policy that has provided us with very stable inflation in the prices of real goods, the prices of assets such as stocks and real estate have continued to fluctuate wildly. Real estate isn’t as bad as stocks, again because of price rigidity—houses rarely have their values re-assessed multiple times per year, let alone multiple times per second. But real estate markets are still unstable, because of so many people trying to speculate on them. We think of real estate as a good way to make money fast—and if you’re lucky, it can be. But in a rational and efficient market, real estate would be almost as boring as stock trading; your profits would be driven entirely by population growth (increasing the demand for land without changing the supply) and the value added in construction of buildings. In fact, the population growth effect should be sapped by a land tax, and then you should only make a profit if you actually build things. Simply owning land shouldn’t be a way of making money—and the reason for this should be obvious: You’re not actually doing anything. I don’t like patent rents very much, but at least inventing new technologies is actually beneficial for society. Owning land contributes absolutely nothing, and yet it has been one of the primary means of amassing wealth for centuries and continues to be today.

But (so-called) investors and the banks and hedge funds they control have little reason to change their ways, as long as the system is set up so that they can keep profiting from the instability that they foster. Particularly when we let them keep the profits when things go well, but immediately rush to bail them out when things go badly, they have basically no incentive at all not to take maximum risk and seek maximum instability. We need a fundamentally different outlook on the proper role and structure of finance in our economy.

Fortunately one is emerging, summarized in a slogan among economically-savvy liberals: Banking should be boring. (Elizabeth Warren has said this, as have Joseph Stiglitz and Paul Krugman.) And indeed it should, for all banks are supposed to be doing is lending money from people who have it and don’t need it to people who need it but don’t have it. They aren’t supposed to be making large profits of their own, because they aren’t the ones actually adding value to the economy. Indeed it was never quite clear to me why banks should be privatized in the first place, though I guess it makes more sense than, oh, say, prisons.

Unfortunately, the majority opinion right now, at least among those who make policy, seems to be that banks don’t need to be restructured or even placed on a tighter leash; no, they need to be set free so they can work their magic again. Even otherwise reasonable, intelligent people quickly become unshakeable ideologues when it comes to the idea of raising taxes or tightening regulations. And as much as I’d like to think that it’s just a small but powerful minority of people who thinks this way, I know full well that a large proportion of Americans believe in these views and intentionally elect politicians who will act upon them.

All the more reason to break from the crowd, don’t you think?

Who are you? What is this new blog? Why “Infinite Identical Psychopaths”?

pnrj core principles, critique of neoclassical economics , , , , , , , , , , , ,

My name is Patrick Julius. I am about halfway through a master’s degree in economics, specializing in the new subfield of cognitive economics (closely related to the also quite new fields of cognitive science and behavioral economics). This makes me in one sense heterodox; I disagree adamantly with most things that typical neoclassical economists say. But in another sense, I am actually quite orthodox. All I’m doing is bringing the insights of psychology, sociology, history, and political science—not to mention ethics—to the study of economics. The problem is simply that economists have divorced themselves so far from the rest of social science.

Another way I differ from most critics of mainstream economics (I’m looking at you, Peter Schiff) is that, for lack of a better phrase, I’m good at math. (As Bill Clinton said, “It’s arithmetic!”) I understand things like partial differential equations and subgame perfect equilibria, and therefore I am equipped to criticize them on their own terms. In this blog I will do my best to explain the esoteric mathematical concepts in terms most readers can understand, but it’s not always easy. The important thing to keep in mind is that fancy math can’t make a lie true; no matter how sophisticated its equations, a model that doesn’t fit the real world can’t be correct.

This blog, which I plan to update every Saturday, is about the current state of economics, both as it is and how economists imagine it to be. One of my central points is that these two are quite far apart, which has exacerbated if not caused the majority of economic problems in the world today. (Economists didn’t invent world hunger, but for over a decade now we’ve had the power to end it and haven’t done so. You’d be amazed how cheap it would be; we’re talking about 1% of First World GDP at most.)

The reason I call it “infinite identical psychopaths” is that this is what neoclassical economists appear to believe human beings are, at least if we judge by the models they use. These are the typical assumptions of a neoclassical economic model:

      1. Perfect information: All individuals know everything they need to know about the state of the world and the actions of other individuals.
      2. Rational expectations: Predictions about the future can only be wrong within a normal distribution, and in the long run are on average correct.
      3. Representative agents: All individuals are identical and interchangeable; a single type represents them all.
      4. Perfect competition: There are infinitely many agents in the market, and none of them ever collude with one another.
      5. “Economic rationality”: Individuals act according to a monotonic increasing utility function that is only dependent upon their own present and future consumption of goods.

I put the last one in scare quotes because it is the worst of the bunch. What economists call “rationality” has only a distant relation to actual rationality, either as understood by common usage or by formal philosophical terminology.

Don’t be scared by the terminology; a “utility function” is just a formal model of the things you care about when you make decisions. Things you want have positive utility; things you don’t want have negative utility. Larger numbers reflect stronger feelings: a bar of chocolate has much less positive utility than a decade of happy marriage; a pinched finger has much less negative utility than a year of continual torture. Utility maximization just means that you try to get the things you want and avoid the things you don’t. By talking about expected utility, we make some allowance for an uncertain future—but not much, because we have so-called “rational expectations”.

Since any action taken by an “economically rational” agent maximizes expected utility, it is impossible for such an agent to ever make a mistake in the usual sense. Whatever they do is always the best idea at the time. This is already an extremely strong assumption that doesn’t make a whole lot of sense applied to human beings; who among us can honestly say they’ve never done anything they later regretted?

The worst part, however, is the assumption that an individual’s utility function depends only upon their own consumption. What this means is that the only thing anyone cares about is how much stuff they have; considerations like family, loyalty, justice, honesty, and fairness cannot factor into their decisions. The “monotonic increasing” part means that more stuff is always better; if they already have twelve private jets, they’d still want a thirteenth; and even if children had to starve for it, they’d be just fine with that. They are, in other words, psychopaths. So that’s one word of my title.

I think “identical” is rather self-explanatory; by using representative agent models, neoclassicists effectively assume that there is no variation between human beings whatsoever. They all have the same desires, the same goals, the same capabilities, the same resources. Implicit in this assumption is the notion that there is no such thing as poverty or wealth inequality, not to mention diversity, disability, or even differences in taste. (One wonders why you’d even bother with economics if that were the case.)

As for “infinite”, that comes from the assumptions of perfect information and perfect competition. In order to really have perfect information, one would need a brain with enough storage capacity to contain the state of every particle in the visible universe. Maybe not quite infinite, but pretty darn close. Likewise, in order to have true perfect competition, there must be infinitely many individuals in the economy, all of whom are poised to instantly take any opportunity offered that allows them to make even the tiniest profit.

Now, you might be thinking this is a strawman; surely neoclassicists don’t actually believe that people are infinite identical psychopaths. They just model that way to simplify the mathematics, which is of course necessary because the world is far too vast and interconnected to analyze in its full complexity.

This is certainly true: Suppose it took you one microsecond to consider each possible position on a Go board; how long would it take you to go through them all? More time than we have left before the universe fades into heat death. A Go board has two colors (plus empty) and 361 spaces. Now imagine trying to understand a global economy of 7 billion people by brute-force analysis. Simplifying heuristics are unavoidable.

And some neoclassical economists—for example Paul Krugman and Joseph Stiglitz—generally use these heuristics correctly; they understand the limitations of their models and don’t apply them in cases where they don’t belong. In that sort of case, there’s nothing particularly bad about these simplifying assumptions; they are like when a physicist models the trajectory of a spacecraft by assuming frictionless vacuum. Since outer space actually is close to a frictionless vacuum, this works pretty well; and if you need to make minor corrections (like the Pioneer Anomaly) you can.

However, this explanation already seems weird for the “economically rational” assumption (the psychopath part), because that doesn’t really make things much simpler. Why would we exclude the fact that people care about each other, they like to cooperate, they have feelings of loyalty and trust? And don’t tell me it’s because that’s impossible to quantify; behavioral geneticists already have a simple equation (C < r B) designed precisely to quantify altruism. (C is cost, B is benefit, r is relatedness.) I’d make only one slight modification; instead of r for relatedness, use p for psychological closeness, or as I like to call it, solidarity. For humans, solidarity is usually much higher than relatedness, though the two are correlated. C < p B.

Worse, there are other neoclassical economists—those of the most fanatically “free-market” bent—who really don’t seem to do this. I don’t know if they honestly believe that people are infinite identical psychopaths, but they make policy as if they did.

We have people like Stephen Moore saying that unemployment is “like a paid vacation” because obviously anyone who truly wants a job can immediately find one, or people like N. Gregory Mankiw arguing—in a published paper no less!—that the reason Steve Jobs was a billionaire was that he was actually a million times as productive as the rest of us, and therefore it would be inefficient (and, he implies but does not say outright, immoral) to take the fruits of those labors from him. (Honestly, I think I could concede the point and still argue for redistribution, on the grounds that people do not deserve to starve to death simply because they aren’t productive; but that’s the sort of thing never even considered by most neoclassicists, and anyway it’s a topic for another time.)

These kinds of statements would only make sense if markets were really as efficient and competitive as neoclassical models—that is, if people were infinite identical psychopaths. Allow even a single monopoly or just a few bits of imperfect information, and that whole edifice collapses.

And indeed if you’ve ever been unemployed or known someone who was, you know that our labor markets just ain’t that efficient. If you want to cut unemployment payments, you need a better argument than that. Similarly, it’s obvious to anyone who isn’t wearing the blinders of economic ideology that many large corporations exert monopoly power to increase their profits at our expense (How can you not see that Apple is a monopoly!?).

This sort of reasoning is more like plotting the trajectory of an aircraft on the assumption of frictionless vacuum; you’d be baffled as to where the oxidizer comes from, or how the craft manages to lift itself off the ground when the exhaust vents are pointed sideways instead of downward. And then you’d be telling the aerospace engineers to cut off the wings because they’re useless mass.

Worst of all, if we continue this analogy, the engineers would listen to you—they’d actually be convinced by your differential equations and cut off the wings just as you requested. Then the plane would never fly, and they’d ask if they could put the wings back on—but you’d adamantly insist that it was just coincidence, you just happened to be hit by a random problem at the very same moment as you cut off the wings, and putting them back on will do nothing and only make things worse.

No, seriously; so-called “Real Business Cycle” theory, while thoroughly obfuscated in esoteric mathematics, ultimately boils down to the assertion that financial crises have nothing to do with recessions, which are actually caused by random shocks to the real economy—the actual production of goods and services. The fact that a financial crisis always seems to happen just beforehand is, apparently, sheer coincidence, or at best some kind of forward-thinking response investors make as they see the storm coming. I want to you think for a minute about the idea that the kind of people who make computer programs that accidentally collapse the Dow, who made Bitcoin the first example in history of hyperdeflation, and who bought up Tweeter thinking it was Twitter are forward-thinking predictors of future events in real production.

And yet, it is on this sort of basis that our policy is made.

Can otherwise intelligent people really believe that these insane models are true? I’m not sure.
Sadly I think they may really believe that all people are psychopaths—because they themselves may be psychopaths. Economics students score higher on various psychopathic traits than other students. Part of this is self-selection—psychopaths are more likely to study economics—but the terrifying part is that part of it isn’t—studying economics may actually make you more like a sociopath. As I study for my master’s degree, I actually am somewhat afraid of being corrupted by this; I make sure to periodically disengage from their ideology and interact with normal people with normal human beliefs to recalibrate my moral compass.

Of course, it’s still pretty hard to imagine that anyone could honestly believe that the world economy is in a state of perfect information. But if they can’t really believe this insane assumption, why do they keep using models based on it?

The more charitable possibility is that they don’t appreciate just how sensitive the models are to the assumptions. They may think, for instance, that the General Welfare Theorems still basically apply if you relax the assumption of perfect information; maybe it’s not always Pareto-efficient, but it’s probably most of the time, right? Or at least close? Actually, no. The Myerson-Satterthwaithe Theorem says that once you give up perfect information, the whole theorem collapses; even a small amount of asymmetric information is enough to make it so that a Pareto-efficient outcome is impossible. And as you might expect, the more asymmetric the information is, the further the result deviates from Pareto-efficiency. And since we always have some asymmetric information, it looks like the General Welfare Theorems really aren’t doing much for us. They apply only in a magical fantasy world. (In case you didn’t know, Pareto-efficiency is a state in which it’s impossible to make any person better off without making someone else worse off. The real world is in a not Pareto-efficient state, which means that by smarter policy we could improve some people’s lives without hurting anyone else.)

The more sinister possibility is that they know full well that the models are wrong, they just don’t care. The models are really just excuses for an underlying ideology, the unshakeable belief that rich people are inherently better than poor people and private corporations are inherently better than governments. Hence, it must be bad for the economy to raise the minimum wage and good to cut income taxes, even though the empirical evidence runs exactly the opposite way; it must be good to subsidize big oil companies and bad to subsidize solar power research, even though that makes absolutely no sense.

One should normally be hesitant to attribute to malice what can be explained by stupidity, but the “I trust the models” explanation just doesn’t work for some of the really extreme privatizations that the US has undergone since Reagan.

No neoclassical model says that you should privatize prisons; prisons are a classic example of a public good, which would be underfunded in a competitive market and basically has to be operated or funded by the government.

No neoclassical model would support the idea that the EPA is a terrorist organization (yes, a member of the US Congress said this). In fact, the economic case for environmental regulations is unassailable. (What else are we supposed to do, privatize the air?) The question is not whether to regulate and tax pollution, but how and how much.

No neoclassical model says that you should deregulate finance; in fact, most neoclassical models don’t even include a financial sector (as bizarre and terrifying as that is), and those that do generally assume it is in a state of perfect equilibrium with zero arbitrage. If the financial sector were actually in a state of zero arbitrage, no banks would make a profit at all.

In case you weren’t aware, arbitrage is the practice of making money off of money without actually making any goods or doing any services. Unlike manufacturing (which, oddly enough, almost all neoclassical models are based on—despite the fact that it is now a minority sector in First World GDP), there’s no value added. Under zero arbitrage, the interest rate a bank charges should be almost exactly the same as the interest rate it receives, with just enough gap between to barely cover their operating expenses—which should in turn be minimal, especially in a modern electronic system. If financial markets were at zero arbitrage equilibrium, it would be sensible to speak of a single “real interest rate” in the economy, the one that everyone pays and everyone receives. Of course, those of us who live in the real world know that not only do different people pay radically different rates, most people have multiple outstanding lines of credit, each with a different rate. My savings account is 0.5%, my car loan is 5.5%, and my biggest credit card is 19%. These basically span the entire range of sensible interest rates (frankly 19% may even exceed that; that’s a doubling time of 3.6 years), and I know I’m not the exception but the rule.

So that’s the mess we’re in. Stay tuned; in future weeks I’ll talk about what we can do about it.