LARS P. SYLL

MMT — the key insights

As has become abundantly clear during the last couple of years, it is obvious that most mainstream economists seem to think that Modern Monetary Theory is something new that some wild heterodox economic cranks have come up with. That is actually very telling about the total lack of knowledge of their own discipline’s history these modern mainstream guys like Summers, Rogoff and Krugman have.

New? Cranks? Reading one of the founders of neoclassical economics, Knut Wicksell, and what he wrote in 1898 on ‘pure credit systems’ in Interest and Prices (Geldzins und Güterpreise) soon makes the delusion go away:

It is possible to go even further. There is no real need for any money at all if a payment between two customers can be accomplished by simply transferring the appropriate sum of money in the books of the bank …

A pure credit system has not yet … been completely developed in this form. But here and there it is to be found in the somewhat different guise of the banknote system …

We intend therefore​, as a basis for the following discussion, to imagine a state of affairs in which money does not actually circulate at all, neither in the form of coin … nor in the form of notes, but where all domestic payments are effected by means of the Giro system and bookkeeping transfers. A thorough analysis of this purely imaginary case seems to me to beworthwhile​e, for it provides a precise antithesis to the equally imaginary​ case of a pure cash system, in which credit plays no part whatever [the exact equivalent of the often used neoclassical model assumption of ‘cash in advance’ – LPS] …

For the sake of simplicity, let us then assume that the whole monetary system of a country is in the hands of a single credit institution, provided with an adequate number of branches, at which each independent economic individual keeps an account on which he can draw cheques.

What Modern Monetary Theory (MMT) basically does is more or less what Wicksell tried to do more than a hundred years ago. The difference is that today the ‘pure credit economy’ is a reality and not just a theoretical curiosity — MMT describes a fiat currency system that almost every country in the world is operating under.

In modern times legal currencies are totally based on fiat. Currencies no longer have intrinsic value (such as gold and silver). What gives them value is basically the simple fact that you have to pay your taxes with them. That also enables governments to run a kind of monopoly business where they never can run out of money. A fortiori, spending becomes the prime mover and taxing and borrowing is degraded to following acts. If we have a depression, the solution, then, is not austerity. It is spending. Budget deficits are not a major problem since fiat money means that governments can always make more of them.​

In the mainstream economist’s world, we don’t need fiscal policy other than when interest rates hit their lower bound (ZLB). In normal times monetary policy suffices. The central banks simply adjust the interest rate to achieve full employment without inflation. If governments in that situation take on larger budget deficits, these tend to crowd out private spending and the interest rates get higher.

What mainstream economists have in mind when they argue this way, is nothing but a version of Say’s law, basically saying that savings have to equal investments and that if the state increases investments, then private investments have to come down (‘crowding out’). As an accounting identity, there is, of course, nothing to say about the law, but as such, it is also totally uninteresting from an economic point of view. What happens when ex-ante savings and investments differ, is that we basically get output adjustments. GDP changes and so makes saving and investments equal ex-post. And this, nota bene, says nothing at all about the success or failure of fiscal policies!

For the benefit of our latter-day​ ‘New Keynesian’ mainstream economists, let’s see what a real Keynesian economist has to say about crowding out and government deficits:

Fallacy 3
Government borrowing is supposed to “crowd out” private investment.

The current reality is that on the contrary, the expenditure of the borrowed funds (unlike the expenditure of tax revenues) will generate added disposable income, enhance the demand for the products of private industry, and make private investment more profitable. As long as there are plenty of idle resources lying around, and monetary authorities behave sensibly, (instead of trying to counter the supposedly inflationary effect of the deficit) those with a prospect for profitable investment can be enabled to obtain financing. Under these circumstances, each additional dollar of deficit will in the medium long run induce two or more additional dollars of private investment. The capital created is an increment to someone’s wealth and ipso facto someone’s saving. “Supply creates its own demand” fails as soon as some of the income generated by the supply is saved, but investment does create its own saving, and more. Any crowding out that may occur is the result, not of underlying economic reality, but of inappropriate restrictive reactions on the part of a monetary authority in response to the deficit.

William Vickrey Fifteen Fatal Fallacies of Financial Fundamentalism

It is true that MMT rejects the traditional Phillips curve inflation-unemployment trade-off and has a less positive evaluation of traditional policy measures to reach full employment. Instead of a general increase in aggregate demand, it usually prefers more ‘structural’ and directed demand measures with less risk of producing increased inflation. At full employment, deficit spending will often be inflationary, but that is not what should decide the fiscal position of the government. The size of public debt and deficits is not — as already Abba Lerner argued with his ‘functional finance’ theory in the 1940s — a policy objective. The size of public debt and deficits are what they are when we try to fulfil our basic economic objectives — full employment and price stability.

That governments can spend whatever amount of money they want is a fact. That does not mean that MMT says they ought to — that’s something our politicians have to decide. No MMTer denies that too much government spending can be inflationary. What is questioned is that government deficits necessarily is inflationary.

The deficit myth

In modern times legal currencies are totally based on fiat. Currencies no longer have intrinsic value (such as gold and silver). What gives them value is basically the simple fact that you have to pay your taxes with them. That also enables governments to run a kind of monopoly business where they never can run out of money. A fortiori, spending becomes the prime mover, and taxing and borrowing are degraded to following acts. If we have a depression, the solution, then, is not austerity. It is spending. Budget deficits are not a major problem since fiat money means that governments can always make more of them.​

In the mainstream economist’s world, we don’t need fiscal policy other than when interest rates hit their lower bound (ZLB). In normal times monetary policy suffices. The central banks simply adjust the interest rate to achieve full employment without inflation. If governments in that situation take on larger budget deficits, these tend to crowd out private spending and the interest rates get higher.

What mainstream economists have in mind when they argue this way, is nothing but a version of Say’s law, basically saying that savings have to equal investments and that if the state increases investments, then private investments have to come down (‘crowding out’). As an accounting identity, there is, of course, nothing to say about the law, but as such, it is also totally uninteresting from an economic point of view. What happens when ex-ante savings and investments differ, is that we basically get output adjustments. GDP changes and so makes saving and investments equal ex-post. And this, nota bene, says nothing at all about the success or failure of fiscal policies!

MMT rejects the traditional Phillips curve inflation-unemployment trade-off and has a less positive evaluation of traditional policy measures to reach full employment. Instead of a general increase in aggregate demand, it usually prefers more ‘structural’ and directed demand measures with less risk of producing increased inflation. At full employment, deficit spending will often be inflationary, but that is not what should decide the fiscal position of the government. The size of public debt and deficits is not — as already Abba Lerner argued with his ‘functional finance’ theory in the 1940s — a policy objective. The size of public debt and deficits are what they are when we try to fulfil our basic economic objectives — full employment and price stability.

Governments can spend whatever amount of money they want. That does not mean that MMT says they ought to — that’s something our politicians have to decide. No MMTer denies that too much government spending can be inflationary. What is questioned is that government deficits necessarily is inflationary.

All real economic activities depend on a functioning financial machinery. But institutional arrangements, states of confidence, fundamental uncertainties, asymmetric expectations, the banking system, financial intermediation, loan granting processes, default risks, liquidity constraints, aggregate debt, cash flow fluctuations, etc., etc. — things that play decisive roles in channelling money/savings/credit — are more or less left in the dark in modern mainstream formalizations of economic theory.

Can a government go bankrupt?
No. You cannot be indebted to yourself.

Can a central bank go bankrupt?
No. A central bank can in principle always ‘print’ more money.

Do taxpayers have to repay government debts?
No, at least not as long the debt is incurred in a country’s own currency.

Do increased public debts burden future generations?
No, not necessarily. It depends on what the debt is used for.

Does maintaining full employment mean the government has to increase its debt?
No.

As the national debt increases, and with it the sum of private wealth, there will be an increasingly yield from taxes on higher incomes and inheritances, even if the tax rates are unchanged. These higher tax payments do not represent reductions of spending by the taxpayers. Therefore the government does not have to use these proceeds to maintain the requisite rate of spending, and can devote them to paying the interest on the national debt …

The greater the national debt the greater is the quantity of private wealth. The reason for this is simply that for every dollar of debt owed by the government there is a private creditor who owns the government obligations (possibly through a corporation in which he has shares), and who regards these obligations as part of his private fortune. The greater the private fortunes the less is the incentive to add to them by saving out of current income …

If for any reason the government does not wish to see private property grow too much … it can check this by taxing the rich instead of borrowing from them, in its program of financing government spending to maintain full employment.

Abba Lerner

Why economics is such an impossible science

In a word, Economics is an Impossible Science because by its own definition the determining conditions of the economy are not economic: they are “exogenous.” Supposedly a science of things, it is by definition without substance, being rather a mode of behavior: the application of scarce means to alternative ends so as to achieve the greatest possible satisfaction—neither means, ends, nor satisfaction substantially specified. Exogenous, however, is the culture, all those meanings, values, institutions, and structures, from gender roles, race relations, food preferences, and ethnicities, to technical inventions, legal regulations, political parties, etc., etc. The effect is a never-ending series of new theoretical breakthroughs, each an Economics du jour worthy of a Nobel prize, consisting of the discovery that some relevant little bit of the culture has something to do with it. Only to be soon superseded and forgotten since the continuous development and transformation of the culture, hence of the economy, leaves the Science in its wake. An impossible Science, by its own premises.

Marshall Sahlins

The increasing mathematization of economics has made mainstream economists more or less obsessed with formal, deductive-axiomatic models. Confronted with the critique that they do not solve real problems, they often react as Saint-Exupéry’s Great Geographer, who, in response to the questions posed by The Little Prince, says that he is too occupied with his scientific work to be able to say anything about reality. Confronting economic theory’s lack of relevance and ability to tackle real problems, one retreats into the wonderful world of economic models. One goes into the “shack of tools” — as my old mentor Erik Dahmén used to say — and stays there. While the economic problems in the world around us steadily increase, one is rather happily playing along with the latest toys in the mathematical toolbox.

Modern mainstream economics is sure very rigorous — but if it’s rigorously wrong, who cares?

Instead of making formal logical argumentation based on deductive-axiomatic models the message, we are better served by economists who more than anything else try to contribute to solving real problems. The motto of John Maynard Keynes is as valid as ever:

It is better to be vaguely right than precisely wrong

In praise of pluralism

Recognition of the speculative value of counterfactualizing provides the grounding for a defense of theoretical pluralism in economics. The existence of multiple contending theories in economics is inconvenient, of course. It casts doubt on the truth content of the counterfactual scenarios generated by the predominant approach and challenges the predominant causal claims … But that is precisely the virtue of contending theoretical perspectives in economics. They serve to generate alternative possible causal linkages that are missed when a profession assembles within one particular church and professes the truth of its sacred texts. Convergence around one theoretical approach generates unwarranted confidence in theoretical propositions and empirical inferences, suppresses recognition of alternative worlds, and restricts the proliferation of alternative scenarios that just might prepare us for unwelcome futures. The consequence of groupthink is repeated surprise when the world takes an unexpected turn for which it is grossly unprepared. The consequence is preventable human suffering …

George F. DeMartino

When mainstream economists today try to give a picture of modern economics as a pluralist enterprise, they silently ‘forget’ to mention that the change and diversity that gets their approval only take place within the analytic-formalistic modelling strategy that makes up the core of mainstream economics. You’re free to take your analytical formalist models and apply them to whatever you want — as long as you do it with a modelling methodology that is acceptable to the mainstream. If you do not follow this particular mathematical-deductive analytical formalism you’re not even considered doing economics. If you haven’t modelled your thoughts, you’re not in the economics business. But this isn’t pluralism. It’s a methodological reductionist straightjacket.

To most mainstream economists you only have knowledge of something when you can prove it, and so ‘proving’ theories with their models via deductions is considered the only certain way to acquire new knowledge. This is, however, a view for which there is no warranted epistemological foundation. Outside mathematics and logic, all human knowledge is conjectural and fallible.

Validly deducing things in closed analytical-formalist-mathematical models — built on atomistic-reductionist assumptions — doesn’t much help us understand or explain what is taking place in the real world we happen to live in. Validly deducing things from patently unreal assumptions — that we all know are purely fictional — makes most of the modelling exercises pursued by mainstream macroeconomists rather pointless. It’s simply not the stuff that real understanding and explanation in science is made of. Had mainstream economists not been so in love with their smorgasbord of models, they would have perceived this too. Telling us that the plethora of models that make up modern macroeconomics ‘are not right or wrong,’ but ‘just more or less applicable to different situations,’ is nothing short of hand waving.

Take macroeconomics as an example. Yes, there is a proliferation of macro models nowadays — but it almost exclusively takes place as a kind of axiomatic variation within the standard DSGE modelling framework. And — no matter how many thousands of models mainstream economists come up with, as long as they are just axiomatic variations of the same old mathematical-deductive ilk, they will not take us one single inch closer to giving us relevant and usable means to further our understanding and explanation of real economies.

Most mainstream economists seem to have no problem with this lack of fundamental diversity — not just path-dependent elaborations of the mainstream canon — and the vanishingly little real-world relevance that characterizes modern macroeconomics. To these economists, there is nothing basically wrong with ‘standard theory.’ As long as policymakers and economists stick to ‘standard economic analysis’ — DSGE — everything is fine. Economics is just a common language and method that makes us think straight and reach correct answers.

Most mainstream neoclassical economists are not for pluralism. They are fanatics insisting on using an axiomatic-deductive economic modelling strategy. To yours truly, this attitude is nothing but a late confirmation of Alfred North Whitehead’s complaint that “the self-confidence of learned people is the comic tragedy of civilisation.”

Mainstream economists today seem to maintain that new imaginative empirical methods — such as natural experiments, field experiments, lab experiments, RCTs — help us to answer questions concerning the validity of economic theories and models.

Yours truly beg to differ. There are few real reasons to share his optimism on the alleged pluralist and empirical revolution in economics.

I am basically — though not without reservations — in favour of the increased use of experiments and field studies within economics. Not least as an alternative to completely barren ‘bridge-less’ axiomatic-deductive theory models. My criticism is more about aspiration levels and what we believe that we can achieve with our mediational epistemological tools and methods in the social sciences.

The increasing use of natural and quasi-natural experiments in economics during the last couple of decades has led several prominent economists to triumphantly declare it as a major step on a recent path toward empirics, where instead of being a deductive philosophy, economics is now increasingly becoming an inductive science.

In randomized trials the researchers try to find out the causal effects that different variables of interest may have by changing circumstances randomly — a procedure somewhat (‘on average’) equivalent to the usual ceteris paribus assumption).

Besides the fact that ‘on average’ is not always ‘good enough,’ it amounts to nothing but hand waving to simpliciter assume, without argumentation, that it is tenable to treat social agents and relations as homogeneous and interchangeable entities.

Randomization is used to basically allow the econometrician to treat the population as consisting of interchangeable and homogeneous groups (‘treatment’ and ‘control’). The regression models one arrives at by using randomized trials tell us the average effect that variations in variable X has on the outcome variable Y, without having to explicitly control for effects of other explanatory variables R, S, T, etc., etc. Everything is assumed to be essentially equal except the values taken by variable X.

Just as e.g. econometrics, randomization promises more than it can deliver, basically because it requires assumptions that in practice are not possible to maintain.

Like econometrics, randomization is basically a deductive method. Real target systems are seldom epistemically isomorphic to our axiomatic-deductive models/systems, and even if they were, we still have to argue for the external validity of the conclusions reached from within these epistemically convenient models/systems. Causal evidence generated by randomization procedures may be valid in ‘closed’ models, but what we usually are interested in, is causal evidence in the real target system we happen to live in.

‘Ideally controlled experiments’ tell us with certainty what causes what effects — but only given the right ‘closures.’ Making appropriate extrapolations from (ideal, accidental, natural or quasi) experiments to different settings, populations or target systems, is not easy. ‘It works there ‘s no evidence for ‘it will work here.’ Causes deduced in an experimental setting still have to show that they come with an export warrant to the target population/system. The causal background assumptions made have to be justified, and without licenses to export, the value of ‘rigorous’ and ‘precise’ methods — and ‘on-average-knowledge’ — is despairingly small.

So, no, I find it hard to share mainstream economists’ enthusiasm and optimism on the value of the latest ’empirical’ trends in mainstream economics. I would argue that although different ’empirical’ approaches have been — more or less — integrated into mainstream economics, there is still a long way to go before economics has become a truly empirical science.

Heterodox critics are not ill-informed about the development of mainstream economics. Its methodology is still the same basic neoclassical one. It’s still non-pluralist. Although more and more economists work within the field of ’empirical’ economics, the foundation and ‘self-evident’ bench-mark is still of the neoclassical deductive-axiomatic ilk.

Sad to say, but we still have to wait for the revolution that will make economics an empirical and truly pluralist and relevant science. Until then, why not read DeMartino’s book The Tragic Science and get a glimpse of the future to come? Mainstream economics belongs to the past.

Post-real economics — a severe case of mathiness

In practice, what math does is let macro-economists locate the FWUTVs [facts with unknown truth values] farther away from the discussion of identification … Relying on a micro-foundation lets an author say, “Assume A, assume B, … blah blah blah … And so we have proven that P is true. Then the model is identified.” …

Distributional assumptions about error terms are a good place to bury things because hardly anyone pays attention to them. Moreover, if a critic does see that this is the identifying assumption, how can she win an argument about the true expected value the level of aether? If the author can make up an imaginary variable, “because I say so” seems like a pretty convincing answer to any question about its properties.

Paul Romer

Yes, indeed, modern mainstream economics — and especially its mathematical-statistical operationalization in the form of econometrics — fails miserably over and over again. Modern mainstream economics is based on the belief that deductive-axiomatic modelling is a sufficient guide to truth. That belief is, however, totally unfounded as long as no proofs are supplied for us to believe in the assumptions on which the model-based deductions and conclusions build. Mathiness masquerading as science is often used by mainstream economists to hide the problematic character of the assumptions used in their theories and models. But — without showing the model assumptions to be realistic and relevant, that kind of economics indeed, as Romer puts it, produces nothing but “blah blah blah.”

The belief that mathematical reasoning is more rigorous and precise than verbal reasoning, which is thought to be susceptible to vagueness and ambiguity, is pervasive in economics. In a celebrated attack on … Paul Krugman, the Chicago economist John Cochrane wrote, ‘Math in economics serves to keep the logic straight, to make sure that the “then” really does follow the “if,” which it so frequently does not if you just write prose.’ But there is a difficulty here which appears to be much more serious in economics than it is in natural sciences: that of relating variables which are written down and manipulated in mathematical models to things that can be identified and measured in the real world … Concepts such as ‘investment specific technology shocks’ and ‘wage markup’ which are no more observable, or well defined, than toves or borogoves. They exist only within the model, which is rigorous only in the same sense as ‘Jabberwocky’ is rigorous; the meaning of each term is defined by the author, and the logic of the argument follows tautologically from these definitions.

Without strong evidence, all kinds of absurd claims and nonsense may pretend to be science. Using math can never be a substitute for thinking. Or as Romer has it in his showdown with post-real economics:

Math cannot establish the truth value of a fact. Never has. Never will.