When does monetary policy become ineffective?

Mark Thoma* leaves a succinct comment on my previous post:

Where we differ is the point at which monetary policy loses its effectiveness - I think that happens way before i-rates hit zero.

It’s an interesting point, because it is a position that many economists (including Keynes himself) seem to have held over the years, but one which, as far as I can tell, has never made much sense.**

I should be more specific: It may make sense if you measure monetary policy in certain ways, but not if you measure monetary policy in the way that is reasonable given how today’s central banks set policy. One might be (but in my opinion shouldn’t be) inclined to measure monetary policy in terms of the volume of open market operations, or some similar measure. In that case, it is quite true that a volume of operations that was effective when the interest rate was 5% is no longer likely to be effective when the interest rate is 1%. And certainly the people responsible for conducting those operations do need to be concerned with the volume. But for us, as economists and such, who can and should view monetary policy with some degree of abstraction, it makes little sense to concern ourselves with the volume of such operations. The transaction costs associated with open market operations are tiny (and not proportional to volume anyhow); the market for Treasury bills to be purchased is vast and quite liquid; the absolute size of an open market operation is of little importance, except inasmuch as it affects other variables, such as interest rates. Moreover, the same argument applies to other “quantitative” measures of monetary policy, such as changes in bank reserves and changes in monetary aggregates.

Since today’s central banks (and the Fed in particular) generally define their policy stance in terms of an interest rate, the reasonable way to measure that stance is in terms of an interest rate. Now one might argue (but again, I don’t think one should) that a proportional change in the interest rate that was effective when the interest rate was high will no longer be effective when the interest rate is low. For example, if the interest rate is 8% and you lop off one fourth of it, making the interest rate 6%, that could be quite an effective policy move; but if the interest rate is 1% and you lop off one fourth of that, making the interest rate 0.75%, that is not likely to be very effective at all by comparison. But central banks don’t measure interest rates proportionally, they measure them in…usually 25 basis point increments. And a 75 basis point cut by the Fed, for example, is considered a big move whether the interest rate starts at 8% or at 3%. The sensible question, it seems to me, is whether the effect of a given cut – defined in basis points – will be diminished when interest rates are already low.

If anything, I would argue, the exact opposite should be true. Monetary policy works largely by affecting the discounted value of expected returns on capital assets. When the Fed cuts interest rates, all other things being equal, stocks are worth more, houses are worth more, factories are worth more, machines are worth more, contemplated investment projects are worth more, and so on. The more the value of an asset rises relative to the cost of producing it, the more it becomes profitable to employ people in producing that asset. And theory says this effect should get stronger the lower are interest rates to begin with.

To see the point, consider a world where the risk premium is not an issue and where the Fed sets long-term interest rates. And just to make it clear, consider the extreme case where “long-term” means perpetual. In that case, the value of an asset that produces a fixed stream of returns equals the value of the periodic return divided by the interest rate. Thus if the Fed were to reduce the interest rate from 5% to 4%, it would increase the value of such an asset by 20%. But if the Fed were to reduce the interest rate from 1% to 0%, it would increase the value of the asset by…well, you do the math. In the enterprise of producing an infinitely valuable asset, it is of course profitable to employ as many people as you possibly can, at whatever wage they might require. In the real world, where the Fed controls only short-term rates, and where there is a risk premium associated with most assets, the effect is not so dramatic, but the difference in the effectiveness of policy when interest rates are low vs. high should certainly be in the same direction.

If, therefore, we may define “monetary policy” as the manipulation of an interest rate by a central bank, then we should expect that monetary policy gains more effectiveness the closer the interest rate comes to zero. And indeed, technically, there is no point at which monetary policy, thus defined, “loses its effectiveness.” There is, of course, a point at which additional stimulative monetary policy becomes impossible to practice, namely, the precise point when the interest rate reaches zero.***



* As far as I know, this is the real Mark Thoma – by which I mean the one that writes Economist’s View – not someone else of the same name. As an aside, though, it occurs to me that there is no shared authentication between Blogger and Typepad, so one doesn’t really know such things for sure. If I wanted to, I could probably post comments on other people’s blogs while pretending to be Brad DeLong or Barry Ritholtz. Or one of them could pretend to be me – though it's hard to think of any reason why they might want to.

** Please do not fear, Gentle Reader, that I have entertained for even a brief moment the abominable heresy that St. Maynard may have held a view that was in any way unreasonable. (Indeed, at the very thought, I must ask you to excuse me while I make the sign of the Keynesian cross over my chest.) Rather, I merely posit that there are certain inherent difficulties in communication between the Truly Awakened and ordinary sentient beings such as we. Interpreting the words of our lord**** in accordance with the mere shadows that form our limited experience, it is we who may have fallen into error. I’m personally intrigued by an alternative exegesis preached to me once by radical political economist Stephen Marglin, who suggests that Keynes was referring not to a lack of effectiveness per se but to the political difficulties in implementing a very low interest rate policy in an economy where the rentier class is loath to give up the income it receives in the form of interest.

***Strictly speaking, this is not quite true. Interest rates on some Treasury bills went below zero in 1938. Apparently, there are some people out there who like their Treasury bills so much that they won’t give them up even if you offer a premium to redemption value.

****I trust that the lower case L keeps me safe from the charge of blasphemy. Surely the lord I have in mind was indeed ours. To whom, after all, could Keynes belong***** if not to the Keynesians.

*****Actually, I have nothing to say down here, but I got so fascinated with the idea of nested footnotes that I decided to push the concept one level further.

Keynes (quoted by DeLong) on Liquidationism

Brad DeLong digs up a nice quote from Keynes, which makes a point similar to what I was trying to argue here, here, and here. I can't claim that the recent US housing boom was either quite as benign or quite as productive as the investment boom of the late 1920s, but the same general principle applies. The behavior of investors in the late 1920s appeared quite reckless in immediate retrospect, but they obviously did more good than harm (or at least, the great harm that resulted indirectly was only because of subsequent bad policies). And we do now, of course, have to be concerned about the risk of inflation, which was not (or shouldn't have been) an issue in the early 1930s. But the idea that speculators have to be severely and broadly punished by the monetary authority for taking excessive risks -- that idea, I contend along with Keynes, is foolish. It is very hard to distinguish which speculative actions were ex ante prudent and/or valuable and which were excessive. It is (as the Fed now clearly realizes) not the job of the central bank to make such judgments after the fact (or, except in its regulatory role, before the fact). The mandate is for high employment and reasonable price stability, and it is not desirable that the mandate should be broadened to include assuring the right incentives for speculators.

Keynesian Fiscal Policy

A conventional “Keynesian” view of fiscal policy holds that the government should run deficits when the economy is weak and surpluses when the economy is strong. Some commentators suggest (as Andrew Samwick does here; hat tip: Brad DeLong) that the budget should be balanced over the business cycle, with no net accumulation of debt. I consider myself a Keynesian, but I think this conventional view is consistent neither with that of Keynes himself nor with what we have learned in the subsequent years.

My alternative view, which I submit for Lord Keynes’ posthumous approval, is that fiscal policy should depend on nominal interest rates. When interest rates are high, for example, it makes no sense to run deficits no matter how weak the economy is. When interest rates are high, the central bank has the option of stimulating the economy by creating more money and pushing interest rates down. If it isn’t doing so already (which, by assumption, it isn’t; otherwise interest rates wouldn’t be high), either the central bankers aren’t very smart (in which case why should we expect the fiscal authorities to be any smarter?) or else they are deliberately keeping the economy weak for some reason. In the latter case, they can be expected to react to any anticipated fiscal stimulus by tightening monetary policy and raising interest rates even further. Indeed, this is just what the Fed did in response the Kemp-Roth tax cut in 1981. I would have recommended running a surplus instead of a deficit under those conditions, even in the depths of the 1982 recession. A fiscal surplus would have minimized the damage done by the tight money policy, and, my guess is, it would not have slowed the recovery materially, because the weak demand would have brought inflation down more quickly, and consequently the Fed would have loosened more quickly.

Now consider an example where interest rates are low. In this case the central bank has the option of slowing down the economy by tightening the money supply and pushing interest rates up, but it may not have the option of stimulating the economy by creating more money and pushing interest rates down. If interest rates are already low, there isn’t much room to push interest rates down, and the stimulus that can be accomplished by this process may be inadequate. And the business cycle is not very predictable. Therefore, even if the economy appears to be growing adequately today, there is no guarantee that it will be doing so tomorrow. In times of low interest rates, fiscal policy should plan for the possibility of a recession by running a deficit, even if economists don’t see a recession as a strong possibility (which, after all, they seldom do, but somehow recessions happen anyway). As long as the central bank isn’t worried about a recession, it can use monetary policy to prevent the economy from overheating, but if it does begin to foresee weakness, it will have room for a stimulus, since the budget deficit will have prevented interest rates from getting too low.

You might object, “What if interest rates stay low and the government keeps borrowing money? We don’t want to pass on these debts to our children (at least Andrew Samwick doesn’t).” My answer – and I think Keynes would have agreed – is, “So what?” For one thing, if interest rates are low, the cost of running a deficit is low. In fact, it can be argued that there is no cost to running a deficit when the interest rate is lower than the growth rate, because the revenue available to pay back the debt will be greater (relative to what needs to be paid) than the revenue available to avoid a deficit in the first place. My own belief is that marginal return on government investment will be sufficient to justify spending levels under these circumstances, but even if it isn’t, the harm done is not great. The harm done by not running sufficient deficits could be quite substantial. And recalling historical periods when interest rates remained low and the government continued borrowing money – the 1930s-1940s in the US and the 1990s-2000s in Japan – I don’t think they regretted the borrowing, and I think most economists would say they didn’t borrow enough.

Plus, I have a more fundamental objection to the idea that passing on debts to our children is unfair. Those who have read my blog from the beginning will feel a sense of déjà vu here, but: Is it unfair to bequeath your children a house with a mortgage? I don’t think so. And I expect there will always be a “house” to go along with the “mortgage” our government leaves to future generations of Americans. In the past it has almost always been the case (across times and places) that each generation left more net economic wealth to the following generation than it had received from the previous one. And in those rare situations where this wasn’t the case, it wasn’t because the generation in question had borrowed too much. My guess is it will continue to be the case in America’s future. If our generation does fail subsequent generations, it will perhaps be because we didn’t spend enough on finding solutions to global warming (or other problems that may plague future generations); it won’t be because we borrowed money to pay for those solutions.

Walking with Keynes

As an alternative to the NAIRU (see these earlier posts and links and explanation), James K. Galbraith argues for an “Old Keynesian” paradigm, in which

full employment was not inherently inflationary; in fact, we saw the greater inflation risk in stagnation itself. In a slowdown, we believe, monopolistic enterprises raise prices in order to try to recover their fixed costs. While on the other hand, full employment production foments ample competition in product markets, high rates of technical change, and declining costs, as businesses seek ways to save on scarce and expensive labor. In other words, productivity growth accelerates because of full employment itself.

I see various difficulties with this point of view. For one thing, slowdowns historically have typically been associated with declining inflation rates, not rising inflation rates. There has been “stagflation,” but generally the “flation” part began before the “stag” part. I don’t doubt that stagnation can cause some firms to raise prices, and that rising interest rates can produce some inflationary feedback, but on balance, tight money (by means, specifically, of the slowdowns it induces) seems to have been a very effective way of reducing the inflation rate. If tight money weren’t the way to do it, one would have to wonder how inflation could possibly be eliminated once it appears.

There is a stronger empirical case to be made, perhaps, for the proposition that booms are not necessarily inflationary. At least there is the salient example of the late 1990s, but even in that case the inflation rate crept upward as the boom moved toward its acme. The rise in inflation rates was more dramatic (though by no means catastrophic) in the more powerful boom of the late 1960s. Generally booms have been associated with moderate but not severe inflation, except in the early (and arguably, again in the late) 1970s when OPEC took advantage of boom conditions by raising oil prices dramatically.

Robert Eisner, whom Galbraith cites as a fellow “Old Keynesian,” argued that booms are in fact not inflationary but slowdowns do have disinflationary effects. In other words, the Phillips curve – the relation between inflation (vertical) and unemployment (horizontal) – is concave, bending downward as it moves to the right. The policy implications are interesting: this view would seem to imply no disadvantage in maintaining a zero interest rate policy during normal conditions. Nonzero interest rates (which would probably end up far from zero) could be reserved for those occasions when inflation (presumably sui generis and unavoidable) needs to be throttled from the system. It’s an intriguing possibility, but one has to be a tad worried about whether the political will to tame such inflations would be forthcoming.

My reading of Keynes’ General Theory, however, suggests an interpretation that is, in some ways, just the opposite. While my Keynes would agree with Eisner’s Keynes that there is a region in which the Phillips curve is fairly flat, my Keynes would say that region is on the right, not on the left. That is, the curve is convex, bending to the right as it moves downward, instead of the other way around.

The policy implications of this view are also interesting: a stimulus policy to raise employment continues to work extremely well up to a point, but then it starts to turn more and more rapidly into an inflationary disaster. This does tend to argue for a “Don’t shoot until you see the whites of their eyes” policy toward inflation, but it also suggests that (1) you want to be cautious about approaching that point and (2) once you get there, you want to make an all-out attack. It also implies that it’s worth devoting a very large amount of resources to finding out just where that inflection point lies. The cost of being wrong in either direction is quite high in terms of either foregone employment or unnecessary inflation.


UPDATE: I should point out that the shape of the Phillips curve (concave, convex, or linear) is a separate issue from whether it has the “accelerationist” property that gives rise to the NAIRU concept. With Eisner's concave Phillips curve, there might still be a NAIRU, but the inflationary cost of going below it would be small, and it would be advantageous to keep unemployment below the NAIRU most of the time and allow a very slow rise in the inflation rate, which could then be brought down again fairly quickly when it started to reach an unacceptable range. The NAIRU idea would not have pleased “my” Keynes, but it is gospel to many contemporary proponents of the convex Phillips curve that I associate with him.

UPDATE2: Added parenthetical links at top.

The Naming of Dogs

A difficult matter: Why does Greg Mankiw have a dog named Tobin? In principle, there are two possible reasons:

(A) he wants to honor Tobin by naming a cherished pet after him;
(B) he wants to dishonor Tobin by naming a mere dog after him.

In practice, I’m sure it’s A, for several reasons (any of which would probably be sufficient):

1. The disrespect (to a Nobel laureate, no less) implied by B would be entirely out of character for Greg.

2. Greg used to have a dog named John Maynard Keynes. At the time, his main claim to fame was as one of the leaders of the “new Keynesian” school of macroeconomics, so it’s implausible that he would have wanted to dishonor Keynes. (It’s also implausible that he would have completely reversed his dog-naming policy subsequently.)

3. I was once at a talk by James Tobin, at which Greg asked a question in a tone that clearly indicated he did not regard Tobin as a dog.

(Actually, possibility C is that his wife named the dog, but I will ignore that possibility for now. Possibility D, which I reject out of hand, in part because of 2 above, is that the name refers to a different Tobin and has nothing to do with the famous economist.)

It seems odd to me that Greg would choose James Tobin out of all the possibilities. When I think about the two of them, it seems there are very few things on which they would agree (if Tobin were alive today). OK, “Keynes was a great economist,” and “Certain nominal quantities values are sticky in the short run.” But beyond that, they would probably disagree about which nominal quantities values (wages or prices), why they are sticky, how long they are sticky, whether the stickiness is symmetric, and so on. They would certainly disagree about the policy implications (e.g., active policy vs. fixed rule). Tobin certainly wouldn’t have taken (or been offered) a job in the Bush administration. Would Mankiw have taken (or been offered) a job in the Kennedy administration? Maybe, but it’s a stretch.

Of course, you can still have great admiration for someone with whom you disagree. But my sense is that there is more to it than that. I think that Greg regards James Tobin as his intellectual progenitor, as an earlier worker on the same project. Perhaps rightly so. I’m not sure what the implications are, but there seems to be some great irony to the whole situation.


UPDATE: I didn’t realize Greg posted on this same topic (sort of) today. Maybe there’s something in the air.

UPDATE2: ...and Greg responds (sort of).

UPDATE3: Shame on me for using the word "quantities" to refer to prices and wages. I really have to mind my P's and Q's.