...against fictions and other tall tales

Monday, 4 May 2020

The macroeconomics of Robert Solow: A partial view

During a hearing before a Congressional Committee on Science and Technology, Robert Solow (MIT) described himself as a "generally quite traditional, mainstream economist".

In my view, either Prof. Solow is unaware of who qualifies as a "traditional, mainstream economist" these days or the definitions of the words "traditional" and "mainstream" need to be completely changed!

Consider, for instance, his views on the notion of "expansionary fiscal consolidation":

[H]ow does a human race with limited intelligence...deal with situations in which the short run need for policy are quite different from the long run need for policy? The feeble-minded, it seems to me, attempt to solve this problem [by asserting] that fiscal consolidation is really expansionary in the short run. I have never been able to understand the mental processes that underlie that statement. But I will take it seriously only -- only -- when its protagonists faced with a situation of clear excess demand propose fiscal expansion. Because if fiscal consolidation is expansionary then fiscal expansion must be contractionary. I don't believe that would happen. So I don't take that argument seriously at all. I think it's cooked up to make a real difficulty go away. (The Feasibility of European Monetary and Fiscal Policies: Rethinking Policy from a Transatlantic Perspective)

...on the supposed lack of microfoundations in Keynesian economics:

You know, there is something a little ludicrous in the belief that microfoundations for macroeconomics were invented some time in the 1970s. If you read Keynes's General Theory or Pigou's Employment and Equilibrium (or many lesser works) you will see that they are full of informal microfoundations. Every author tries to make his behavioral assumptions plausible by talking about the way that groups or ordinary economic agents might be expected to act...But you can recall Keynes's argument that the marginal propensity to consume should be between zero and one, or his discussion about whether the marginal efficiency of investment should be sensitive to current output or should depend primarily on "the state of long-term expectations". Those are microfoundations. (2004, p. 659)

...on the claim there is a connection between the money supply and price level:

[T]he financial press sometimes writes as though there is some special direct connection between the money supply and price level. So far as fundamentals are concerned, monetary policy works through its effects on aggregate nominal demand, just like fiscal policy, in the long run, too. The only direct connection I can think of is itself the creation of pop economics. If business people and others become convinced that there is some causal immaculate connection from the money supply to the price level, completely bypassing the real economy, then the news of a monetary-policy action will generate inflationary or disinflationary expectations and induce the sorts of actions that will tend to bring about the expected outcome and thus confirm the expectations and strengthen the underlying beliefs. (1998:4)

...on the problem with Milton Friedman's reliance on correlations between and M and other variables to infer policy conclusions and the assumption of an exogenous money supply (with John Kareken):

The unreliability of this line of argument is suggested by the following reducto ad absurdum. Imagine an economy buffeted by all kinds of cyclical forces, endogenous and exogenous. Suppose that by heroic, and perhaps even cyclical variation in the money stock and its rate of change, the Federal Reserve manages deftly to counter all disturbing impulses and to stabilize the level of economic activity absolutely. Then an observer following the Friedman method would see peaks and troughs in monetary changes accompanied by a steady level of economic activity. He would presumably conclude that monetary policy has no effects at all, which would be precisely the opposite of the truth. (Karaken and Solow, 1963, p. 16)

...on choosing the right model in macroeconomics:

[I] believe rather strongly that the "right" model for an occasion depends on the context --  the institutional context, of course -- but also on the current mix of beliefs, attitudes, norms, and "theories" that inhabits the minds of businessmen, bankers, consumers, and savers. (2004, p.xi)

...on the problems with the DSGE model:

I do not think that the currently popular DSGE models pass the smell test. They take it for granted that the whole economy can be thought about as if it were a single, consistent person or dynasty carrying out a rationally designed, long-term plan, occasionally disturbed by unexpected shocks, but adapting to them in a rational, consistent way. I do not think that this picture passes the smell test. The protagonists of this idea make a claim to respectability by asserting that it is founded on what we know about microeconomic behavior, but I think that this claim is generally phony. The advocates no doubt believe what they say, but they seem to have stopped sniffing or to have lost their sense of smell altogether. (For more, see here and here)

...on the difference between budgetary and real resources costs:

The trouble is that the great world -- including a large part of the intellectual world -- has lost sight of the fundamental difference between budgetary costs and real resource costs. An unemployed worker and an underutilized or idle plant is not something we're saving up for the future. Today's labor can't be used next year or the year after. And the machine time in a plant that's down can't be redone two years from now or three years from now. Three years from now we hope that the plant will be running for current uses. So there's that important sense in which idle resources are almost - and maybe literally - free to the economy. The problem is to get them used in a reasonable way. (see 22:00 here):

...on the importance of fiscal policy for stabilization purposes:

I start from the belief that non-trivial imbalances of aggregate supply and demand do occur in modern industrial capitalist economies, and last long enough that public policy should not ignore them...When such imbalances occur, fiscal policy is a useful tool. The single instrument of monetary policy can not do justice to the multiplicity of policy objectives; and the Ricardian equivalence claim is in practice not nearly enough to convince a realist of the ineffectiveness of fiscal policy. The real obstacles to the rational conduct of fiscal policy are the uncertainties about the proper target for real output and employment, and the tendency for stabilization goals to become inextricably tangled in and distracted by distributional and allocational controversy. (Is fiscal policy possible? Is it desirable?, p. 23)

...on the long run potency of deficit spending financed by bonds vs. deficits financed by money creation, and on the contractionary nature of open market purchases of government bonds (with Alan Blinder):

[N]ot only is deficit spending financed by bonds expansionary in the long run, it is even more expansionary than the same spending financed by the creation of money. [Foonote: An interesting corollary of this is that an open-market purchase, i.e. a swap of B for M by the government with G unchanged, will be contractionary!] (Blinder and Solow: Does Fiscal Policy Matter? 1973)

...on how statements by a central bank can influence how the public translates relative price changes into expectations about the consumer price index:

There are various interest groups in the economy: bankers, investors, savers, lenders, borrowers, buyers and sellers and what not. There is no reason for them to react in the same way. How does one aggregate expectations?

...on the use of "expectations" to explain macro policy outcomes:

[T]o rest the whole argument on expectations -- that all-purpose unobservable -- just stops rational discussion in its tracks. I agree that the expectations, beliefs, theories, and prejudices of market participants are all important determinants of what happens. The trouble is that there is no outcome or behavior pattern that cannot be explained by one or another drama starring expectations. Since none of us can measure expectations (whose?) we have a lot of freedom to write the scenario we happen to like today. Should I respond...by writing a different play, starring somewhat different expectations? No thanks, I'd rather look at data. (1998:93)

...on the claim of self-correcting markets and the role of aggregate demand in causing output fluctuations:

Capitalist economies do not behave like well-oiled equilibrium machines. For all sorts of reasons they can stray above or below potential output for meaningful periods of time, though apparently they are sightly more likely to stray below than above. Even apart from considerations of growth, macro policy should lean in the general direction that will nudge aggregate demand toward potential, whenever a noticeable gap occurs. The relevant point is that this strategy is also growth-promoting. Whatever the level of real interest rates, excessively weak aggregate demand -- and the prospect of weak and fluctuating aggregate demand -- works against investment. Few things are as bad for expected return on investment as weak and uncertain future sales...Successful stabilization contributes to growth too. (Role of macroeconomic policy, p. 301)

...on the need for public policy to address the unemployment of unskilled labor:

It needs to be insisted that the root of the problem lies in the enormous range of earning capacities generated by the interaction of modern technology (and other influences on the demand for unskilled labor) with the demographic and educational outcomes on the supply side of the labor market. There is no really good way for a market economy to deal humanely with that spread. (Too Optimistic)

...on the fallacy of self-correcting markets and the limits of monetary policy during deep recessions:

One important lesson that I hope we have learned from the crisis and the deep recession still going on is that economies like ours can experience uncomfortably long intervals of general excess supply or excess demand. Of course, we -- economists and interested civilians -- used to know that. But it was widely forgotten during the Great Moderation and the accompanying optimism among economists and civilians about smoothly self-correcting markets. The general belief than was that monetary policy was an adequate tool for taking care of any minor blip. During long and deep recessions, however, it has become evident that monetary policy may reach its limits without being able to generate enough aggregate demand to close the excess supply gap. (IMF Talk: Macro and Growth Policies)

...on the problems with Ricardian equivalence:

What might interfere with [the claim that it is optimal for households to save a tax reduction]? Any number of things: if households had been unable to consume as much as their optimal plan required because they lacked liquid assets and could not borrow freely, then the added liquidity provided by the tax reduction would enable them to consumer more now. If the Treasury were a more efficient, less risky, borrower than many households, then the appearance of some new public debt would also affect real behavior. And, of course, if consumers do not look ahead very far or very carefully, if they give little weight to the interests of descendants, or if they tend to ignore or underestimate the future implications of current budgetary actions, then Ricardian equivalence will fail, and tax reduction financed by borrowing will indeed be expansionary. All those "if" clauses strike me as very likely to be real and quantitatively important, and that suggests that Ricardian equivalence is not a practically significant limitation on fiscal policy. (Is fiscal policy possible? Is it desirable?, p. 12)

...on the problem with the natural rate of unemployment hypothesis:

Let me try to explain what nags at me in all this...We are left here with a theory whose two central concepts, the natural rate of unemployment or output and the expected rate of inflation have three suspicious characteristics in common. They are not directly observable. They are not very well defined. And, so far as we can tell, they move around too much for comfort -- they are not stable. I suspect this is an intrinsic difficulty. I have no wish to minimize the importance of, say, inflationary expectations. But we are faced with a real problem: here is a concept that seems in our minds to play an important role in macro behavior, and yet it's very difficult to deal with because it escapes observation and it even escapes clear definition. 

On the natural rate of unemployment, I think the behavior of the profession exhibits problems. In order to make sensible use of this kind of theory, you want the natural rate of unemployment to be a fairly stable quantity. It won't do its job if it jumps around violently from one year to the next. But that's what seems to happen. We, the profession, are driven to explaining events by inventing movements of the natural rate, which we have not observed and have not very well defined. The issue came up first in the passage of the big European economies from 2 percent unemployment, on average, to 8 or 9 percent unemployment, on average, within a few years. The only way to explain that within the standard model is to say that the natural rate of unemployment must have increased from something like 2 percent to something like 8 or 9 percent. The actual facts that could account for any such dynamics never seemed to me or to any critical person to be capable of explaining so big a change. So we are left with inventing changes in the natural rate of unemployment to explain the facts, and it is all done in our heads, not in any tested model. I regret to say that you often find this kind of reasoning: the inflation rate is increasing because the unemployment rate is below the natural rate. How do you know that the unemployment rate is below the natural rate? Because the inflation rate is increasing. I think we are all good enough logicians to realize that this is exactly equivalent to saying that the rate of inflation is increasing, and nothing more. 

It seems to me that we ought to be thinking much more about the determinants of whatever you choose to call it. I hate to use the phrase "natural rate" but of course I do. It was a masterpiece of persuasive definition by Milton. Who could ever want an unnatural rate of unemployment? (Fifty years of the Phillips Curve: A Dialogue on what we have learned, p.84)

...and more on the natural rate of unemployment:

There is nothing like an adjustable, unobservable parameter to keep a theory afloat in rough seas...I think the doctrine [of the natural rate of unemployment] to be theoretically and empirically as soft as a grape. To say that in the long run the unemployment rate tends to return to the natural rate of unemployment is to say almost nothing. In the long run the unemployment rate goes where it goes. You can call where it goes the natural rate; but unless you have a more convincing story than I have seen about the length of the long run and the location of the natural rate, you are only giving a tendentious name to a vague concept (1998, pp. 9, 91)


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  3. Jos Laliberté6 May 2020 at 04:18

    Great read! Many things that are relevant to our current predicament on the economic front. In particular this: "Whatever the level of real interest rates, excessively weak aggregate demand -- and the prospect of weak and fluctuating aggregate demand -- works against investment. Few things are as bad for expected return on investment as weak and uncertain future sales.."
    What is your take on economic impact of Covid-19 and how best to prepare for the recovery? (and apply the teachings of Robert Solow)

    1. Yeah, Solow is on the mark here! About covid, the optimist in me says that we can expect the type of investment to be different (less emphasis to support collective activities such as concerts and cruises, and more investment into organizational tools and human capital to support a community less prone to pandemics). While my bias has traditionally been on the optimistic side, I'm somewhat pessimistic about the prospect of virtuous investment in communities.

      The lockdowns are having both temporary and long term impacts, and I think the long term ones will be hard to counter, especially in regard to small businesses which will likely shut down for ever due to the sudden shock caused by the drop in aggregate demand. Also, so much in the economy is focused on tourism and travel; how can increased spending by governments make up that shortfall when no one wants to travel anymore.

      "Aggregate demand" is defined as willingness and ability to spend. Covid has the potential to kill people's willingness to spend, even as they have the ability to do so.

      Looking forward to Stiglitz talking about this stuff. He usually provides "big picture" solutions that fit with the spirit of the times.

  4. Actually, come to think about it, people have short memories and once the number of cases stop this summer, people will slowly get on with their lives. But I think it'll be a while before people hop on planes and cruise ships the way they once did. Unemployment will take a while to get better and this is why spending will take a while to get back to "normal".