Bayes versus Science Round Two: Battle of the Banks

In the beginning, before people had quite understood how economics worked, they’d gone around thinking crazy ideas like “Businessmen choose so as to maximize profits” and “Firms set the marginal cost [pay] of their workers equal to the marginal product revenue [output] of their workers.”

Of course people noticed the problem right away: people observably don’t make decisions to do things like maximize profits or set MC equal to MR. Economists responded by saying that people somehow implicitly used rules like “maximize profits” or “set MC equal to MR” as guidelines for behavior.

Then in 1939 a group of Oxford economists decided to test the theory: do firms use “set MC equal to MR” as a rule for setting the pay of workers? They sent out questionnaires to firms asking them how they set their workers’ pay.

The responses they got back were highly disturbing. Firms didn’t know what this marginal cost and marginal revenue business was and they didn’t much care. They used a kind of pricing called “full-cost pricing” which...didn’t make much sense and it’s not very important. What is important is that the results of the questionnaires struck a huge blow to marginalism. Firms aren’t using marginal cost to make decisions!

And so the full-cost pricing controversy was born.

There was a huge debate in the profession. Was marginalism wrong? Were firms not profit-maximizing entities? Some of the greatest economic minds of that generation took part in the debate. But for all their effort there didn’t seem to be any satisfactory way to explain the data that would also preserve most of the advances in economic theory since the 1870s.

Then Armen Albert Alchian, the 1000 year-old vampire of economics, entered the fray. In eleven elegant pages he ended the debate and changed economics forever.

Alchian pointed out that it is only in a world of certainty and perfect foresight that people can choose to maximize profits or set MR equal to MC. Neither of those things are actions, they are outcomes—there is no button you can press to maximize profits or set MR equal to MC. In the world of certainty and perfect foresight, however, there may as well be a button—you can just look down all the paths your different actions lead to to see which path leads to the highest profits. It’s easy, for someone with certainty and perfect foresight.

But in reality, there is uncertainty and imperfect foresight. Imperfect foresight means that the button pressing-equivalent of looking down all the different paths you can take to see which one leads to the highest profits is not possible.

Uncertainty means that when you consider the consequences of your choices, you don’t face a single potential outcome but rather a distribution of outcomes, and furthermore, that distribution overlaps with the distribution generated by other actions. Uncertainty is a consequence of the immense complexity of the economy, which is made of an uncountable number of ever-changing parts. And in that case, “maximize profits” or “set MR equal to MC” is in no way a useful guide to action. There is a single maximizing outcome but you can’t choose that. You can only choose different distributions, and because the distributions overlap, there is no maximizing distribution. There is an optimal distribution, whichever distribution you happen to prefer, but maximization is out as a guide to action.

So what is to become of economic theory if firms can’t choose to maximize profits and set MR equal to MC?

Not to worry, Alchian said. That’s what the economy is for.

The economy is competitive. That means there is a set of criteria which the economy selects for. Firms with that criteria are promoted and firms without that criteria go out of business. Yes, just like evolution by natural selection; the economy is evolutionary.

Alchian pointed out that what the economy selects for is realized positive profits. Basically, that means the economy promotes the firms that make more money than their competitors. Firms that make less money than their competitors go out of business—they die.

Those realized positive profits are achieved by the firm that is best adapted to its environment, in exactly the same way that those organisms which reproduce successfully are best adapted to their environments. Therefore the competitive economy, by directly selecting for realized positive profits, indirectly selects for the firms which do the best job of solving the economic problem they are presented with.

What that means, Alchian realized, is that you don’t need any individual in the economy doing anything particularly “economic” like trying to maximize profits or set MR equal to MC for the economy itself to achieve exactly that. You can have people with zero foresight, and as long as they can just try all kinds of things, the economy will select for the firms that do the best job of approximating the characteristics best suited to the environment.

Say two firms compete with each other: one sells tulips, and the other roses. Which, if either, is profit maximizing—which is ideal for the current economic environment? Probably neither, but it doesn’t matter; the economy will promote the firm that makes more money and kill the firm that makes less. The plans and rationales of the two different firms for their actions are irrelevant.

Two more firms go at it: one tries to somehow achieve “full-cost pricing” and the other tries to somehow set MR equal to MC. Alchian’s point is that neither firm actually knows that it can accomplish its goal with its chosen strategy. The economy will choose the firm which makes more money, which is the firm better suited to the environment, and the economy will kill the firm that makes less money.

What Alchian’s analysis shows is that you can have an economy full of people who just make silly decisions for no rational reason and still have rational economic outcomes if the competitive economy selects for those outcomes. What economists had thought is that firms adapt themselves to the economy, but Alchian showed that it is more like the economy which adapts firms to it. And thus, “consistent success cannot be treated as prima facie evidence against pure luck!”

Marginalism is saved! The full-cost pricing controversy has ended. People don’t need to maximize profits or set MR equal to MC as long as the economy selects for realized positive profits and having MR set equal to MC a characteristic of a firm ideally suited for the given economic environment.

What no one realized at the time, not even Alchian, who was soon busy using the stock market to figure out which materials are used to make nuclear bombs, is that Alchian’s argument destroys the case for central banking.

Let’s consider central banking versus free banking from this angle: which system has greater science power, i.e., if we think of the economic environment as posing a problem to the two systems, which system is more likely to solve that problem?

The power to solve a problem comes in two steps: generating hypotheses, and testing hypotheses.

Free banking generates hypotheses by, well, letting people try whatever they please. But it’s not quite as random as that, or nothing would ever be accomplished. Just as in evolution by natural selection, as long as the environment has not changed too dramatically, using what already exists as the starting point allows you to cut a long way through the search space to a hypothesis not extremely far from the most correct answer.

But people are smarter than evolution. They don’t just have to stop with what they are currently experimenting a mutation on. They can look at the past or at other industries for inspiration. They can also use their own insight to cut even farther past the answer the economy has already produced. This results in failures, certainly, but also in brilliant innovations at a rate and scale evolution by natural selection cannot match.

That is how free banking generates hypotheses: dozens, hundreds, or maybe even thousands of hypotheses, some big, some small, are constantly being proposed, where proposed means the number of hypotheses submitted for testing. They use the given answer as a starting point and use their own knowledge of changing economic conditions, past and parallel evidence, and their own insight to go even further. This is a very different and superior system to evolution by natural selection, which simply takes the current hypothesis and tries a small random change. It can’t look at past or parallel hypotheses and the change is random since no intelligence is applied.

Now compare this to how central banking generates hypotheses. Central banking, like free banking, can only propose as many hypotheses as it is able to test, which is much smaller than what free banking can do both because central banks want to experiment less and because there are fewer of them to begin with.

Central banking can’t match free banking’s rate of hypothesis generation, but if central banking can generate hypotheses as good as the best free banking hypotheses with fewer hypotheses, that’s actually a point in central banking’s favor—it’s more efficient with its hypotheses. But central banking probably can’t do that. That’s simply because central banking, like free banking, can’t go much farther in its hypotheses than by looking at what it is already doing, what it has done, and what other central banks are doing parallel to it. But the range of hypotheses attempted by the central bank is much more limited than free banking. You simply can’t try as many different kinds of things with a central bank. The consequences of a central bank filled with experimental spirit would be disastrous. Central banking could only outperform free banking if it started out much closer to the most correct hypothesis than free banking did. But that is extremely implausible. To see why we have to go back to Alchian.

In the real world of uncertainty and perfect foresight, central banks can’t just press a button setting inflation, unemployment, and economic growth at the desired levels.

(Although you might wonder if something like the Mind Projection Fallacy doesn’t occur when economists play at being central bankers. The individuals in the model might not know everything about their small world but the modeler, the economist certainly does, and so in his model the solution will be obvious to him, and if he doesn’t realize that that’s a fact about his mind and not about the world, then he would be overconfident in the central bank’s foresight and ability to achieve its goals by the decision-equivalent of button pressing)

What central banks actually face is a set of overlapping distributions of outcomes with no maximizing distribution due to the extreme complexity of economy. There is no certain or clear path to the goals of the central bank.

Free banking also faces this problem, but there are two key differences.

The first key difference is that free banking is much more decentralized than central banking. A more decentralized system means that the problems the individuals are trying to solve are much smaller and simpler (although still possibly very large and complex), and the problem-solvers have more information about the problem. It’s a smaller problem and they are closer to it. The more centralized system faces a more complex system and has less information to solve it with. Free banking is thus more likely to generate some hypotheses that are better than what central banking produces.

The second difference has to do the relative ability of free and central banking to test their hypotheses, the second aspect of scientific power.

Alchian showed that even if individuals want to maximize profits and set MR equal to MC, in a world of uncertainty and imperfect foresight the idea of choosing to maximize profits simply doesn’t make sense. The economy is simply too complex for people to adapt themselves to it very effectively. But that doesn’t matter, because the economy adapts people to it. The economy selects for the firms with realized positive profits, which is to say, firms which are relatively well-suited for the given environment, and the economy kills the firms which are relatively unsuited for the given environment.

In other words, the market economy tests hypotheses. All those hypotheses constantly generated by free banking are subject to a brutal, merciless test: the test of survival in the marketplace. It is this constant, terrible series of tests that allows market economies to produce outcomes that economics can explain and predict when economics has very little ability to explain or predict individual behavior.

This is free banking’s greatest advantage over central banking, because central banking does not test its hypotheses. The central bank does not profit for generating a good hypothesis and it does not die for generating a bad one. The central bank does not face the trial, the test, the selection.

Imagine a group of biologists who created a few types of organisms which they intended to be well-suited to some environment, and then never released those organisms into the environment to subject them to evolutionary pressures. They would have no way of knowing which organisms were better suited to that environment and which weren’t. Scientific power depends strongly on whether you can do the test. People who can’t test their hypotheses don’t get very far with them.

The different quality of the tests free and central banking subject their hypotheses too brings us back around to their relative ability to generate quality hypotheses. Both rely on looking at what they are already doing and have done to serve as a starting point for new hypotheses, but the difference is that free banking’s starting point is a starting point forged in the furnaces of scientific testing, and central banking’s starting point is pretty much whatever central banks happen to be doing, which may appear to be working or not. If it does appear to be working, uncertainty means there is no way of knowing whether that is sheer luck or if the hypothesis is actually a good one. Free banking has a powerful test, however, for determining its surviving hypotheses and so can be more confident that its surviving hypotheses are actually good.

The verdict is clear: the scientific power of free banking is dramatically superior to that of central banking. Free banking generates a larger quantity of hypotheses, the most accurate of which are more accurate than the hypotheses central banking generates, and then goes through a much more exacting testing process which kills off the bad hypotheses and rewards the good ones with profits. Central banking, on the other hand, is left wondering if any success it is seeing is because of the good hypothesis or sheer dumb luck, because there is no trial, no test to distinguish.

You might notice, at the end of all this, that the process free banking goes through to adapt and be adapted to the environment closely resembles the scientific method. People come up with hypotheses that seem smart to them based on what they know about past results, and then they do the experiment. The hypotheses that pass the test are promoted and the hypotheses that fail are discarded.

Central banking, on the other hand, more closely resembles armchair philosophy of the sort that science rebelled against centuries ago. A small number of very smart people are supposed to figure the world out largely by thinking about it. Sure, they have reams of data and theory, but so did Aristotle (hey, every time he looked outside he was receiving all kinds of data). Aristotle’s weakness was that he didn’t do experiments, not a lack of access to data or raw intelligence. By the same token, central banking’s weakness is its inability to test its hypotheses.

(And so perhaps it’s not entirely surprising that central banking pre-dates economics itself, and is essentially an outgrowth of a feudal institution. Whereas in every other industry there were significant movements in the past several centuries towards the ending of privilege and monopoly, the freeing up of competition and trade, central banks maintained their monopolies and privileges and even were established in countries that had previously lacked them. And so the methodology of central banking is still essentially pre-scientific.)

This isn’t the end of the argument, of course. There are all kinds of obstacles to successful coordination in a free banking regime (for example externalities, predatory pricing, information asymmetry), but then again the same is true in a central banking regime (for example terrible incentives, lack of Hayekian information, political interference). At best for the case for central banking, these kinds of problems on net wash out.

Which means, given how much stronger free banking is as a scientific process than central banking, that free banking wins outright, even though I can’t do the experiment to prove it. It’s simply a much more plausible hypothesis.

(This is not a defense of free banking. Nothing in this argument establishes that free banking is the best banking regime, and I do not intend to present that argument. It isn’t interesting to me. But this argument does show that if you want an alternative to free banking, that alternative can’t be central banking.)

And it’s so ironic, that for all the desire economists and laypeople have expressed over the years for a scientific alternative to capitalism, that a competitive market economy is the embodiment of the scientific method in the global economy, working on a scale beyond the current abilities of any scientist or team of scientist to solve problems that the world’s best economists cannot even begin to solve in their entirety.