Archive for the 'Noah Smith' Category

Noah Smith on Bitcoins: A Failure with a Golden Future

Noah Smith and I agree that, as I argued in my previous post, Bitcoins have no chance of becoming a successful money, much less replacing or displacing the dollar as the most important and widely used money in the world. In a post on Bloomberg yesterday, Noah explains why Bitcoins are nearly useless as money, reiterating a number of the points I made and adding some others of his own. However, I think that Bitcoins must sooner or later become worthless, while Noah thinks that Bitcoins, like gold, can be a worthwhile investment for those who think that it is fiat money that is going to become worthless. Here’s how Noah puts it.

So cryptocurrencies won’t be actual currencies, except for drug dealers and other people who can’t use normal forms of payment. But will they be good financial investments? Some won’t — some will be scams, and many will simply fall into disuse and be forgotten. But some may remain good investments, and even go up in price over many decades.

A similar phenomenon has already happened: gold. Legendary investor Warren Buffett once ridiculed gold for being an unproductive asset, but the price of the yellow metal has climbed over time:

Why has gold increased in price? One reason is that it’s not quite useless — people use gold for jewelry and some industrial applications, so the metal slowly goes out of circulation, increasing its scarcity.

And another reason is that central banks now own more than 17% of all the gold in the world. In the 1980s and 1990s, when the value of gold was steadily dropping to as little as $250 an ounce, central banks were selling off their unproductive gold stocks, until they realized that, in selling off their gold stocks, they were driving down the value of all the gold sitting in their vaults. Once they figured out what they were doing, they agreed among themselves that they would start buying gold instead of selling it. And in the early years of this century, gold prices started to rebound.

But another reason is that people simply believe in gold. In the end, the price of an asset is what people believe it’s worth.

Yes, but it sure does help when there are large central banks out there buying unwanted gold, and piling it up in vaults where no one else can do anything with it.

Many people believe that fiat currencies will eventually collapse, and that gold will reemerge as the global currency.

And it’s the large central banks that issue the principal fiat currencies whose immense holdings of gold reserves that keep the price of gold from collapsing.

That narrative has survived over many decades, and the rise of Bitcoin as an alternative hasn’t killed it yet. Maybe there’s a deeply embedded collective memory of the Middle Ages, when governments around the world were so unstable that gold and other precious metals were widely used to make payments.

In the Middle Ages, the idea of, and the technology for creating, fiat money had not yet been invented, though coin debasement was widely practiced. It took centuries before a workable system for controlling fiat money was developed.

Gold bugs, as advocates of gold as an investment are commonly known, may simply be hedging against the perceived possibility that the world will enter a new medieval period.

How ill-mannered of them not to thank central banks for preventing the value of gold from collapsing.

Similarly, Bitcoin or other cryptocurrencies may never go to zero, even if no one ends up using them for anything. They represent a belief in the theory that fiat money is doomed, and a hedge against the possibility that fiat-based payments systems will one day collapse. When looking for a cryptocurrency to invest in, it might be useful to think not about which is the best payments system, but which represents the most enduring expression of skepticism about fiat money itself.

The problem with cryptocurrencies is that there is no reason to think that central banks will start amassing huge stockpiles of cryptocurrencies, thereby ensuring that the demand for cryptocurrencies will always be sufficient to keep their value at or above whatever level the central banks are comfortable with.

It just seems odd to me that some people want to invest in Bitcoins, which provide no present or future real services, and almost no present or future monetary services, in the belief that it is fiat money, which clearly does provide present and future monetary services, and provides the non-trivial additional benefit of enabling one to discharge tax liabilities to the government, is going to become worthless sometime in the future.

If your bet that Bitcoins are going to become valuable depends on the forecast that dollars will become worthless, you probably need to rethink your investment strategy.

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Price Stickiness and Macroeconomics

Noah Smith has a classically snide rejoinder to Stephen Williamson’s outrage at Noah’s Bloomberg paean to price stickiness and to the classic Ball and Maniw article on the subject, an article that provoked an embarrassingly outraged response from Robert Lucas when published over 20 years ago. I don’t know if Lucas ever got over it, but evidently Williamson hasn’t.

Now to be fair, Lucas’s outrage, though misplaced, was understandable, at least if one understands that Lucas was so offended by the ironic tone in which Ball and Mankiw cast themselves as defenders of traditional macroeconomics – including both Keynesians and Monetarists – against the onslaught of “heretics” like Lucas, Sargent, Kydland and Prescott that he just stopped reading after the first few pages and then, in a fit of righteous indignation, wrote a diatribe attacking Ball and Mankiw as religious fanatics trying to halt the progress of science as if that was the real message of the paper – not, to say the least, a very sophisticated reading of what Ball and Mankiw wrote.

While I am not hostile to the idea of price stickiness — one of the most popular posts I have written being an attempt to provide a rationale for the stylized (though controversial) fact that wages are stickier than other input, and most output, prices — it does seem to me that there is something ad hoc and superficial about the idea of price stickiness and about many explanations, including those offered by Ball and Mankiw, for price stickiness. I think that the negative reactions that price stickiness elicits from a lot of economists — and not only from Lucas and Williamson — reflect a feeling that price stickiness is not well grounded in any economic theory.

Let me offer a slightly different criticism of price stickiness as a feature of macroeconomic models, which is simply that although price stickiness is a sufficient condition for inefficient macroeconomic fluctuations, it is not a necessary condition. It is entirely possible that even with highly flexible prices, there would still be inefficient macroeconomic fluctuations. And the reason why price flexibility, by itself, is no guarantee against macroeconomic contractions is that macroeconomic contractions are caused by disequilibrium prices, and disequilibrium prices can prevail regardless of how flexible prices are.

The usual argument is that if prices are free to adjust in response to market forces, they will adjust to balance supply and demand, and an equilibrium will be restored by the automatic adjustment of prices. That is what students are taught in Econ 1. And it is an important lesson, but it is also a “partial” lesson. It is partial, because it applies to a single market that is out of equilibrium. The implicit assumption in that exercise is that nothing else is changing, which means that all other markets — well, not quite all other markets, but I will ignore that nuance – are in equilibrium. That’s what I mean when I say (as I have done before) that just as macroeconomics needs microfoundations, microeconomics needs macrofoundations.

Now it’s pretty easy to show that in a single market with an upward-sloping supply curve and a downward-sloping demand curve, that a price-adjustment rule that raises price when there’s an excess demand and reduces price when there’s an excess supply will lead to an equilibrium market price. But that simple price-adjustment rule is hard to generalize when many markets — not just one — are in disequilibrium, because reducing disequilibrium in one market may actually exacerbate disequilibrium, or create a disequilibrium that wasn’t there before, in another market. Thus, even if there is an equilibrium price vector out there, which, if it were announced to all economic agents, would sustain a general equilibrium in all markets, there is no guarantee that following the standard price-adjustment rule of raising price in markets with an excess demand and reducing price in markets with an excess supply will ultimately lead to the equilibrium price vector. Even more disturbing, the standard price-adjustment rule may not, even under a tatonnement process in which no trading is allowed at disequilibrium prices, lead to the discovery of the equilibrium price vector. Of course, in the real world trading occurs routinely at disequilibrium prices, so that the “mechanical” forces tending an economy toward equilibrium are even weaker than the standard analysis of price-adjustment would suggest.

This doesn’t mean that an economy out of equilibrium has no stabilizing tendencies; it does mean that those stabilizing tendencies are not very well understood, and we have almost no formal theory with which to describe how such an adjustment process leading from disequilibrium to equilibrium actually works. We just assume that such a process exists. Franklin Fisher made this point 30 years ago in an important, but insufficiently appreciated, volume Disequilibrium Foundations of Equilibrium Economics. But the idea goes back even further: to Hayek’s important work on intertemporal equilibrium, especially his classic paper “Economics and Knowledge,” formalized by Hicks in the temporary-equilibrium model described in Value and Capital.

The key point made by Hayek in this context is that there can be an intertemporal equilibrium if and only if all agents formulate their individual plans on the basis of the same expectations of future prices. If their expectations for future prices are not the same, then any plans based on incorrect price expectations will have to be revised, or abandoned altogether, as price expectations are disappointed over time. For price adjustment to lead an economy back to equilibrium, the price adjustment must converge on an equilibrium price vector and on correct price expectations. But, as Hayek understood in 1937, and as Fisher explained in a dense treatise 30 years ago, we have no economic theory that explains how such a price vector, even if it exists, is arrived at, and even under a tannonement process, much less under decentralized price setting. Pinning the blame on this vague thing called price stickiness doesn’t address the deeper underlying theoretical issue.

Of course for Lucas et al. to scoff at price stickiness on these grounds is a bit rich, because Lucas and his followers seem entirely comfortable with assuming that the equilibrium price vector is rationally expected. Indeed, rational expectation of the equilibrium price vector is held up by Lucas as precisely the microfoundation that transformed the unruly field of macroeconomics into a real science.

Two Cheers (Well, Maybe Only One and a Half) for Falsificationism

Noah Smith recently wrote a defense (sort of) of falsificationism in response to Sean Carroll’s suggestion that the time has come for scientists to throw falisficationism overboard as a guide for scientific practice. While Noah isn’t ready to throw out falsification as a scientific ideal, he does acknowledge that not everything that scientists do is really falsifiable.

But, as Carroll himself seems to understand in arguing against falsificationism, even though a particular concept or entity may itself be unobservable (and thus unfalsifiable), the larger theory of which it is a part may still have implications that are falsifiable. This is the case in economics. A utility function or a preference ordering is not observable, but by imposing certain conditions on that utility function, one can derive some (weakly) testable implications. This is exactly what Karl Popper, who introduced and popularized the idea of falsificationism, meant when he said that the aim of science is to explain the known by the unknown. To posit an unobservable utility function or an unobservable string is not necessarily to engage in purely metaphysical speculation, but to do exactly what scientists have always done, to propose explanations that would somehow account for some problematic phenomenon that they had already observed. The explanations always (or at least frequently) involve positing something unobservable (e.g., gravitation) whose existence can only be indirectly perceived by comparing the implications (predictions) inferred from the existence of the unobservable entity with what we can actually observe. Here’s how Popper once put it:

Science is valued for its liberalizing influence as one of the greatest of the forces that make for human freedom.

According to the view of science which I am trying to defend here, this is due to the fact that scientists have dared (since Thales, Democritus, Plato’s Timaeus, and Aristarchus) to create myths, or conjectures, or theories, which are in striking contrast to the everyday world of common experience, yet able to explain some aspects of this world of common experience. Galileo pays homage to Aristarchus and Copernicus precisely because they dared to go beyond this known world of our senses: “I cannot,” he writes, “express strongly enough my unbounded admiration for the greatness of mind of these men who conceived [the heliocentric system] and held it to be true […], in violent opposition to the evidence of their own senses.” This is Galileo’s testimony to the liberalizing force of science. Such theories would be important even if they were no more than exercises for our imagination. But they are more than this, as can be seen from the fact that we submit them to severe tests by trying to deduce from them some of the regularities of the known world of common experience by trying to explain these regularities. And these attempts to explain the known by the unknown (as I have described them elsewhere) have immeasurably extended the realm of the known. They have added to the facts of our everyday world the invisible air, the antipodes, the circulation of the blood, the worlds of the telescope and the microscope, of electricity, and of tracer atoms showing us in detail the movements of matter within living bodies.  All these things are far from being mere instruments: they are witness to the intellectual conquest of our world by our minds.

So I think that Sean Carroll, rather than arguing against falisficationism, is really thinking of falsificationism in the broader terms that Popper himself laid out a long time ago. And I think that Noah’s shrug-ability suggestion is also, with appropriate adjustments for changes in expository style, entirely in the spirit of Popper’s view of falsificationism. But to make that point clear, one needs to understand what motivated Popper to propose falsifiability as a criterion for distinguishing between science and non-science. Popper’s aim was to overturn logical positivism, a philosophical doctrine associated with the group of eminent philosophers who made up what was known as the Vienna Circle in the 1920s and 1930s. Building on the British empiricist tradition in science and philosophy, the logical positivists argued that our knowledge of the external world is based on sensory experience, and that apart from the tautological truths of pure logic (of which mathematics is a part) there is no other knowledge. Furthermore, no meaning could be attached to any statement whose validity could not checked either by examining its logical validity as an inference from explicit premises or verified by sensory experience. According to this criterion, much of human discourse about ethics, morals, aesthetics, religion and much of philosophy was simply meaningless, aka metaphysics.

Popper, who grew up in Vienna and was on the periphery of the Vienna Circle, rejected the idea that logical tautologies and statements potentially verifiable by observation are the only conveyors of meaning between human beings. Metaphysical statements can be meaningful even if they can’t be confirmed by observation. Metaphysical statements are meaningful if they are coherent and are not nonsensical. If there is a problem with metaphysical statements, the problem is not necessarily because they have no meaning. In making this argument, Popper suggested an alternative criterion of demarcation to that between meaning and non-meaning: a criterion of demarcation between science and metaphysics. Science is indeed different from metaphysics, but the difference is not that science is meaningful and metaphysics is not. The difference is that scientific statements can be refuted (or falsified) by observations while metaphysical statements cannot be refuted by observations. As a matter of logic, the only way to refute a proposition by an observation is for the proposition to assert that the observation was not possible. Unless you can say what observation would refute what you are saying, you are engaging in metaphysical, not scientific, talk. This gave rise to Popper’s then very surprising result. If you positively assert the existence of something – an assertion potentially verifiable by observation, and hence for logical positivists the quintessential scientific statement — you are making a metaphysical, not a scientific, statement. The statement that something (e.g., God, a string, or a utility function) exists cannot be refuted by any observation. However the unobservable phenomenon may be part of a theory with implications that could be refuted by some observation. But in that case it would be the theory not the posited object that was refuted.

In fact, Popper thought that metaphysical statements not only could be meaningful, but could even be extremely useful, coining the term “metaphysical research programs,” because a metaphysical, unfalsifiable idea or theory could be the impetus for further research, possibly becoming scientifically fruitful in the way that evolutionary biology eventually sprang from the possibly unfalsifiable idea of survival of the fittest. That sounds to me pretty much like Noah’s idea of shrug-ability.

Popper was largely successful in overthrowing logical positivism, though whether it was entirely his doing (as he liked to claim) and whether it was fully overthrown are not so clear. One reason to think that it was not all his doing is that there is still a lot of confusion about what the falsification criterion actually means. Reading Noah Smith and Sean Carroll, I almost get the impression that they think the falsification criterion distinguishes not just between science and non-science but between meaning and non-meaning. Otherwise, why would anyone think that there is any problem with introducing an unfalsifiable concept into scientific discussion. When Popper argued that science should aim at proposing and testing falsifiable theories, he meant that one should not design a theory so that it can’t be tested, or adopt stratagems — ad hoc hypotheses — that serve only to account for otherwise falsifying observations. But if someone comes up with a creative new idea, and the idea can’t be tested, at least given the current observational technology, that is not a reason to reject the theory, especially if the new theory accounts for otherwise unexplained observations.

Another manifestation of Popper’s imperfect success in overthrowing logical positivism is that Paul Samuelson in his classic The Foundations of Economic Analysis chose to call the falsifiable implications of economic theory, meaningful theorems. By naming those implications “meaningful theorems,” Samuelson clearly was operating under the positivist presumption that only a proposition that could (at least in principle) be falsified by observation was meaningful. However, that formulation reflected an untenable compromise between Popper’s criterion for distinguishing science from metaphysics and the logical positivist criterion for distinguishing meaningful from meaningless statements. Instead of referring to meaningful theorems, Samuelson should have called them, more modestly, testable or scientific theorems.

So, at least as I read Popper, Noah Smith and Sean Carroll are only discovering what Popper already understood a long time ago.

At this point, some readers may be wondering why, having said all that, I seem to have trouble giving falisficationism (and Popper) even two cheers. So I am afraid that I will have to close this post on a somewhat critical note. The problem with Popper is that his rhetoric suggests that scientific methodology is a lot more important than it really is. Apart from some egregious examples like Marxism and Freudianism, which were deliberately formulated to exclude the possibility of refutation, there really aren’t that many theories entertained by scientists that can be ruled out of order on strictly methodological grounds. Popper can occasionally provide some methodological reminders to scientists to avoid relying on ad hoc theorizing — at least when a non-ad-hoc alternative is handy — but beyond that I don’t think methodology counts for very much in the day to day work of scientists. Many theories are difficult to falsify, but the difficulty is not necessarily the result of deliberate choices by the theorists, it is the result of the nature of the problem and the nature of the evidence that could potentially refute the theory. The evidence is what it is. It is nice to come up with a theory that predicts a novel fact that can be observed, but nature is not always so accommodating to our theories.

There is a kind of rationalistic (I am using “rationalistic” in the pejorative sense of Michael Oakeshott) faith that following the methodological rules that Popper worked so hard to formulate will guarantee scientific progress. Those rules tend to encourage an unrealistic focus on making theories testable (especially in economics) when by their nature the phenomena are too complex for theories to be formulated in ways that are susceptible to decisive testing. And although Popper recognized that empirical testing of a theory has very limited usefulness unless the theory is being compared to some alternative theory, too often discussions of theory testing are in the context of testing a single theory in isolation. Kuhn and others have pointed out that science is not routinely carried out in the way that Popper suggested it should be. To some extent, Popper acknowledged the truth of that observation, though he liked to cite examples from the history of science to illustrate his thesis, but argued that he was offering a normative, not a positive, theory of scientific discovery. But why should we assume that Popper had more insight into the process of discovery for particular sciences than the practitioners of those sciences actually doing the research? That is the nub of the criticism of Popper that I take away from Oakeshott’s work. Life and any form of endeavor involves the transmission of ways of doing things, traditions, that cannot be reduced to a set of rules, but require education, training, practice and experience. That’s what Kuhn called normal science. Normal science can go off the tracks too, but it is naïve to think that a list of methodological rules is what will keep science moving constantly in the right direction. Why should Popper’s rules necessarily trump the lessons that practitioners have absorbed from the scientific traditions in which they have been trained? I don’t believe that there is any surefire recipe for scientific progress.

Nevertheless, when I look at the way economics is now being practiced and taught, I can’t help but think that a dose of Popperianism might not be the worst thing that could be administered to modern economics. But that’s a discussion for another day.


About Me

David Glasner
Washington, DC

I am an economist in the Washington DC area. My research and writing has been mostly on monetary economics and policy and the history of economics. In my book Free Banking and Monetary Reform, I argued for a non-Monetarist non-Keynesian approach to monetary policy, based on a theory of a competitive supply of money. Over the years, I have become increasingly impressed by the similarities between my approach and that of R. G. Hawtrey and hope to bring Hawtrey's unduly neglected contributions to the attention of a wider audience.

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