Scott’s prediction market

Scott Sumner has long argued that the Federal Reserve or the US Treasury should help set-up a NGDP futures markets and conduct monetary policy based on market expectations of NGDP. This is a great idea, but so far it does not really look like the Fed is interested in the idea.

However, there is another and far more simple possibility. Scott should just drop the good people at Iowa Electronic Markets (IEM) a mail and ask them to set up a “prediction market” on future US NGDP. They would probably be happy to play along – after all this is the sexiest idea in US monetary debate today.

So what is IEM? It is “a group of real-money prediction markets/futures markets operated by the University of Iowa Tippie College of Business. Unlike normal futures markets, the IEM is not-for-profit; the markets are run for educational and research purposes. The IEM allows traders to buy and sell contracts based on, among other things, political election results and economic indicators. Some markets are only available to academic traders. The political election results have been highly accurate, especially when compared with traditional polling. This may be because it uses a free market model to predict an outcome, instead of the aggregation of many individuals’ opinions. The speculator is more interested in a correct outcome than in his or her desired outcome.” (Stolen from Wikipedia).

Prediction markets have been very successful in predicting the outcome of for example US presidential elections so why should prediction market not be able to predict NGDP two, three or fours year out in the future? At least prediction market based forecasts of NGDP will be as good as any in-house forecast from the Fed.

How would it work? IEM would set up a bet on US NGDP for 2012, 2013 and 2018. Scott is presently recommending that the Fed should aim for bringing back NGDP to the pre-crisis trend and thereafter target a growth path of 5%. The outcome from the prediction market can then be compared with Scott’s target path – if the predicted numbers are below Scott’s preferred path then he has “market backing” for claiming US monetary policy is too tight…and maybe even Ben Bernanke would play a long…

PS If IEM are not up for the challenge then the good people at the Holly Stock Exchange might be up for it – Scott after all is fast becoming a big celebrity.

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UPDATE: Just found out somebody else got the same idea (before me) – see Chris Fox and John Salvatier at  “Good morning, Economics”.

Friedman provided a theory for NGDP targeting

A distinct feature of Market Monetarist thinking is that our starting point for monetary analysis is nominal income and that monetary policy determines nominal income or nominal GDP (NGDP). This is contrary to New Keynesian analysis where monetary policy determines real GDP, which in turn determines inflation via a Phillips curve.

Hence, to Market Monetarists the split between prices and quantities is not a monetary matter. Monetary policy determines NGDP and that is all that monetary policy can do. While we acknowledge that there is a high correlation between real GDP and NGDP in the short-run the causality runs from NGDP to RGDP and not the other way. In the long run inflation is determined as a residual between NGDP, which is a monetary phenomenon, and RGDP, which is determined by supply side factors.

Milton Friedman came to the same conclusion 40 years ago. In a much overlooked (or should I say a forgotten) article from 1971 “A Monetary Theory of Nominal Income” he discusses this topic. The paper is a follow up on “Milton Friedman’s Monetary Framework” in which Friedman discusses his monetary framework with his critics. I have always felt that he failed to explain what he really meant in his “Monetary Framework”. Friedman seems to have realised that himself and his 1971 try to make up this failure.

Here is Friedman:

“In … “A Theoretical Framework for Monetary Analysis,” I outlined a simple model of six equations in seven variables that was consistent with both the quantity theory of money and the Keynesian income-expenditure theory…The difference between the two theories is in the missing equation the quantity theory adds an equation stating that real income is determined outside the system (the assumption of “full employment”); the income-expenditure theory adds an equation stating that the price level is determined outside the system (the assumption of price or wage rigidity)…The present addendum to my earlier paper suggests a third way to supply the missing equation. This third way involves bypassing the breakdown of nominal income between real income and prices and using the quantity theory to derive a theory of nominal income rather than a theory of either prices or real income. While I believe that this third way is implicit in that part of my theoretical and empirical work on money that has been concerned with short-period fluctuations, I have not heretofore stated it explicitly. This third way seems to me superior to the other two ways as a method of closing the theoretical system for the purpose of analyzing short-period changes. At the same time, it shares some of the defects common to the other two ways that I listed in the earlier paper.”

Hence, Friedman here acknowledges that the problem in the “Framework” papers was that he tried to come up with a monetary theory that followed a Keynesian route from RGDP to prices rather than “bypassing the breakdown of nominal income between real income and prices and using the quantity theory to derive a theory of nominal income”. 

This is something completely lost in modern macroeconomic thinking, which see monetary policy working through a Phillips curve. This is somewhat odd given the weak empirical foundation for the existence of a Phillips curve.

I will not get into the details of Friedman’s model, but I would note that it could be interesting to see how it would look in a rational expectations version.

Back to Friedman:

“I have not, before this, written down explicitly the particular simplification I have labeled the monetary theory of nominal income-although Meltzer has referred to the theory underlying Anna Schwartz’s and my Monetary History as a “theory of nominal income” (Meltzer 1965, p. 414). But once written down, it rings the bell, and seems to me to correspond to the broadest framework implicit in much of the work that I and others have done in analyzing monetary experience. It seems to me also to be consistent with many of our findings. I do not propose here to attempt a full catalog of the findings, but I should like to suggest a number and, more important, to indicate the chief defect that I find with the framework.”

Here Friedman acknowledges that his empirical work for example on the Great Depression is based on a monetary theory of nominal income rather than on a quasi-Keynesian model (like the one he presents in his “Framework”). Any Market Monetarist would of course agree that a monetary theory of nominal income is needed to explain the Great Depression and the Great Recession for that matter. Friedman continues:

“One finding that we have observed is that the relation between changes in the nominal quantity of money and changes in nominal income is almost always closer and more dependable than the relation between changes in real income and the real quantity of money or between changes in the quantity of money per unit of output and changes in prices. This result has always seemed to me puzzling, since a stable demand function for money with an income elasticity different from unity led me to expect the opposite. Yet the actual finding would be generated by the approach of this paper, with the division between prices and quantities determined by variables not explicitly contained in it.”

This empirical result is highly interesting – the correlation between money and NGDP is stronger than between money and prices and income. In that regard it seems odd that Friedman never endorsed NGDP targeting – after all it would be natural to endorse a monetary policy rule that actually is directed towards something monetary policy can determine. However, there is no doubt that Friedman’s 1971 paper clearly provides the theoretical foundation for NGDP targeting. It is only too bad Friedman never came to that conclusion.

Finally I should say that Market Monetarists like David Beckworth and Josh Hendrickson are working on developing a modern monetary theory of nominal income determination.

PS Scott Sumner in a recent comment also discuss the relationship between NGDP, prices and quantities in Keynesian and (Market) Monetarist models.

PPS It should be noted that Bennett McCallum in a number of papers refers to Friedman’s 1971 paper when he argues in favour of nominal income targeting. See for example “Nominal Income Targeting in an Open-Economy Optimizing Model”

The Market Monetarist voice at Cato Institute

In a pervious post I have noted that Tim Lee a scholar at the libertarian Cato Institute has been endorsing basically Market Monetarist ideas. Now Tim has a comment on Market Monetarism. I am happy to see that Tim has nice things to say about Market Monetarism and my paper on Market Monetarism in his latest article at forbes.com.

Once again – I am happy to see that Tim Lee is continuing the work for nominal income targeting that William Niskanen started at the Cato Institute. NGDP should be the natural position of the good people at the Cato Institute.

Tim Lee – Market Monetarist

Timothy B. Lee at the Cato Institute has a couple of interesting comments out on US monetary policy – they are at the core very much Market Monetarist.

Here is a few recommendations:

Fighting the Last Monetary War (Happy to see Tim is reading Friedman’s Money Mischief – one of my favourite books)
More on Nominal Sales and Monetary Policy (happy to see a tribute to William Niskanen’s monetary policy views)
Beckworth, Ponnuru and Niskanen on Monetary Policy (Tim, you make us proud…)

Most Market Monetarists talk about NGDP level targeting, but I guess people like Beckworth and Woolsey would prefer targeting “nominal final sales to domestic purchasers” as William Niskanen suggested. I have sympathy for that as well – especially if I think of none-US monetary policy then a target on what I would call final domestic spending would be appropriate. Furthermore, final sales was also Clark Warburton’s prefered measure for Py and given I think Warburton is the most underappreciated monetarist ever it is only natural for me to advocate to use final sales rather NGDP as a measure of Py.

Anyway, nice to see a Cato scholar on board. The Cato Institute has been at the forefront of “policy development” in the US for decades and it’s annual monetary conference continues to be hugely influential on US and global thinking about monetary policy and theory so it is truly great that Tim is spreading the message from William Niskanen.

Beckworth and Ponnuru: Tight budgets, Loose money

David Beckworth and Ramesh Ponnuru just came out with a new article on the economic policy debate in the US. Beckworth and Ponnuru lash out against both left and right in American politics. Let me just say that I agree with basically everything in the article, but you should read it yourself.

However, what I find most interesting in the article is not the discussion about the US political landscape, but rather the very clear description of both the Great Moderation and the causes for the Great Recession:

“The Fed did a pretty good job of stabilizing the economy. The result of its monetary policies was that the economy, measured in current-dollar or “nominal” terms, grew at about 5 percent a year, with inflation accounting for 2 percent of the increase and real economic growth 3 percent. Keeping nominal spending and nominal income on a predictable path is important for two reasons. First, most debts, such as mortgages, are contracted in nominal terms, so an unexpected slowdown in nominal income growth increases their burden. Also, the difficulty of adjusting nominal prices makes the business cycle more severe. If workers resist nominal wage cuts during a deflation, for example, mass unemployment results…During the great moderation, people began to expect spending and incomes to grow at a stable rate and made borrowing decisions based on it. But maintaining this stability requires the Fed to increase the money supply whenever the demand for money balances—people’s preference for cash over other assets—increases. This happened in 2008 when, as a result of the recession and the financial crisis, fearful Americans began to hold their cash. The Federal Reserve, first worried about increased commodity prices as a harbinger of inflation and then focused on saving the financial system, failed to increase the money supply enough to offset this shift in demand and allowed nominal spending to fall through mid-2009″

I wish a lot more people would understand this – Beckworth and Ponnuru are certainly not to blame if you don’t understand it yet.

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UPDATE: See this interesting comment on Niskanen and Beckworth/Ponnuru by Tim B. Lee.

William Niskanen 1933-2011

William Niskanen passed away on October 26. I have always admired Niskanen a lot. He was a champion of liberty and a great economist.

Any student of Public Choice theory would know Niskanen’s classic Bureaucracy and Representative Government from 1971 and I still think of this as his greatest contribution to economic theory. However, as Bill Woolsey reminds us William Niskanen was also a long time proponent of nominal income targeting.

Niskanen first advocated nominal income targeting or rather targeting of nominal spending in his 1992 paper “Political Guidance on Monetary Policy”. Niskanen later elaborated on the subject in his 2001 paper “A test of the Demand Rule” and further in his 2002 paper “On the Death of the Phillips Curve”.

Marcus Nunes has an insight comment on “A test of the Demand Rule” here.

The Chuck Norris effect, Swiss lessons and a (not so) crazy idea

Here is from The Street Light:

“You may recall that in September the Swiss National Bank (SNB) announced that it was going to intervene as necessary in the currency markets to ensure that the Swiss Franc (CHF) stayed above a minimum exchange rate with the euro of 1.20 CHF/EUR. How has that been working out for them?

It turns out that it has been working extremely well. Today the SNB released data on its balance sheet for the end of September. During the month of August the SNB had to spend almost CHF 100 billion to buy foreign currency assets to keep the exchange rate at a reasonable level. But in September — most of which was after the announcement of the exchange rate minimum — the SNB’s foreign currency assets only grew by about CHF 25 billion. Furthermore, this increase in the CHF value of the SNB’s foreign currency assets likely includes substantial capital gains that the SNB reaped on its euro portfolio (which was valued at about €130 bn at the end of September), as the CHF was almost 10% weaker against the euro in September than in August. Given that, it seems likely that the SNB’s purchases of new euro assets in September after the announcement of the exchange rate floor almost completely stopped.”

This is a very strong demonstration of the power of monetary policy when the central bank is credible. This is the Chuck Norris effect of monetary policy: You don’t have to print more money to ease monetary policy if you are a credible central bank with a credible target. (Nick Rowe and I like this sort of thing…)

And now to the (not so) crazy idea – if the SNB can ease monetary policy by announcing a devaluation why can’t the Federal Reserve and the ECB do it? Obviously some would say that not all central banks in the world can devalue at the same time – but they can. They can easily do it against commodity prices. So lets say that the ECB, the Federal Reserve, the Bank of Japan, the Bank of England and the SNB tomorrow announced a 15% devaluation against commodity prices (for example the CRB index) and that they will defend that one sided “peg” until the nominal GDP level returns to their pre-Great Recession trend levels. Why 15%? Because that is more or less the NGDP “gap” in the euro zone and the US.

The clever reader will notice that this is the coordinated and slightly more sexy version of Lars E. O. Svensson’s fool-proof way to escape deflation and the liquidity trap.

Is a coordinated 15% devaluation of the major currencies of the world (with the exception of RMB) a crazy idea? Yes, it is quite crazy and it could trigger all kind of political discussions, but I am pretty sure it would work and would very fast bring US and European NGDP back towards the pre-crisis trend. And for those who now scream at the screen “How the hell will higher commodity prices help us?” I will just remind you of the crucial difference between demand and supply driven increases in commodity prices. But okay, lets say we don’t want to do that – so lets instead do the following. The same central banks will “devalue” 15% against a composite index for stock prices in the US, the UK, the euro zone and Japan. Ok, I know you are very upset now. How can he suggest that? I am not really suggesting it, but I am arguing that monetary policy can easily work and all this “crazy idea” would actually do the trick and bring back NGDP back on track in both the US and Europe.  But you might have a better idea.

George Selgin on Bernanke and NGDP targeting

Bill Woolsey has comment on Fed governor Ben Bernanke’s comment’s yesterday regarding NGDP targeting.

Here is what Bernanke said:

“So the fed’s mandate is, of course, a dual mandate. We have a mandate for both employment and for price stability. And we have a framework in place that allows us to communicate and to think about the two sides of that mandate. We talked yesterday about nominal GDP as an indicator, as an information variable, something to add to the list of variables that we think about. And it was a very interesting discussion. However, we think that within the existing framework that we have, which looks at both sides of the mandate, not just some combination of the two, we can communicate whatever we need to communicate about future monetary policy. So we are not contemplating at this time any radical change in framework. We are going to stay within the dual mandate approach that we’ve been using until this point.”

George Selgin who is one of the pioneers of NGDP targeting – even though we all know George prefers Free Banking – has a comment on Bill’s blog. I think George’s comment make a lot of sense:

“Right. BB doesn’t get it: nominal spending isn’t an indicator to be used in helping the Fed to regulate P and y. It is itself the very thing the Fed ought to regulate. The idea that Py is some sort of composite of two more “fundamental” variables, where the Fed is supposed to be concerned with the stability of each, is a crude fallacy. Neither stability of y nor that of P is desirable per se. Stability of Py, on the other hand–which is to say stability of nominal aggregate demand–is desirable in itself.”

Right on George! (for those not schooled in econ lingo P is prices and y is real GDP and Py obviously is nominal GDP).

“Ben Volcker” and the monetary transmission mechanism

I am increasingly realising that a key problem in the Market Monetarist arguments for NGDP level targeting is that we have not been very clear in our arguments concerning how it would actually work.

We argue that we should target a certain level for NGDP and then it seems like we just expect it too happen more or less by itself. Yes, we argue that the central bank should control the money base to achieve this target and this could done with the use of NGDP futures. However, I still think that we need to be even clearer on this point.

Therefore, we really need a Market Monetarist theory of the monetary transmission mechanism. In this post I will try to sketch such a theory.

Combining “old monetarist” insights with rational expectations

The historical debate between “old” keynesians and “old” monetarists played out in the late 1960s and the 1970s basically was centre around the IS/LM model.

The debate about the IS/LM model was both empirical and theoretical. On the hand keynesians and monetarists where debating the how large the interest rate elasticity was of money and investments respectively. Hence, it was more or less a debate about the slope of the IS and LM curves. In much of especially Milton Friedman writings he seems to accept the overall IS/LM framework. This is something that really frustrates me with much of Friedman’s work on the transmission mechanism and other monetarists also criticized Friedman for this. Particularly Karl Brunner and Allan Meltzer were critical of “Friedman’s monetary framework” and for his “compromises” with the keynesians on the IS/LM model.

Brunner and Meltzer instead suggested an alternative to the IS/LM model. In my view Brunner and Meltzer provides numerous important insights to the monetary transmission mechanism, but it often becomes unduly complicated in my view as their points really are relatively simple and straight forward.

At the core of the Brunner-Meltzer critique of the IS/LM model is that there only are two assets in the IS/LM model – basically money and bonds and if more assets are included in the model such as equities and real estate then the conclusions drawn from the model will be drastically different from the standard IS/LM model. It is especially notable that the “liquidity trap” argument breaks down totally when more than two assets are included in the model. This obviously also is key to the Market Monetarist arguments against the existence of the liquidity trap.

This mean that monetary policy not only works via the bond market (in fact the money market). In fact we could easily imagine a theoretical world where interest rates did not exist and monetary policy would work perfectly well. Imagining a IS/LM model where we have two assets. Money and equities. In such a world an increase in the money supply would push up the prices of equities. This would reduce the funding costs of companies and hence increase investments. At the same time it would increase holdholds wealth (if they hold equities in their portfolio) and this would increase private consumption. In this world monetary policy works perfectly well and the there is no problem with a “zero lower bound” on interest rates. Throw in the real estate market and a foreign exchange markets and then you have two more “channels” by which monetary policy works.

Hence, the Market Monetarist perspective on monetary policy the following dictum holds:

“Monetary policy works through many channels”

Keynesians are still obsessed about interest rates

Fast forward to the debate today. New Keynesians have mostly accepted that there are ways out of the liquidity trap and the work of for example Lars E. O. Svensson is key. However, when one reads New Keynesian research today one will realise that New Keynesians are as obsessed with interest rates as the key channel for the transmission of monetary policy as the old keynesians were. What has changed is that New Keynesians believe that we can get around the liquidity trap by playing around with expectations. Old Keynesians assumed that economic agents had backward looking or static expectations while New Keynesians assume rational expectations – hence, forward-looking expectations.

Hence, New Keynesians still see interest rates at being at the core of monetary policy making. This is as problematic as it was 30 years ago. Yes, it is fine that New Keynesian acknowledges that agents are forward-looking but it is highly problematic that they maintain the narrow focus on interest rates.

In the New Keynesian model monetary policy works by increasing inflation expectation that pushes down real interest rates, which spurs private consumption and investments. Market Monetarists certainly do think this is one of many channels by which monetary policy work, but it is clearly not the most important channel.

Rules are at the centre of the transmission mechanism

Market Monetarist stresses the importance of monetary policy rules and how that impacts agents expectations and hence the monetary transmission mechanism. Hence, we are more focused on the forward-looking nature or monetary policy than the “old” monetarists were. In that regard we are similar to the New Keynesians.

It exactly because of our acceptance of rational expectations that we are so obsessed about NGDP level targeting. Therefore when we discuss the monetary policy transmission mechanism it is key whether we are in world with no credible rule in place or whether we are in a world of a credible monetary policy rule. Below I will discussion both.

From no credibility to a credible NGDP level target

Lets assume that the economy is in “bad equilibrium”. For some reason money velocity has collapsed, which continues to put downward pressures on inflation and growth and therefore on NGDP. Then enters a new credible central bank governor and he announces the following:

“I will ensure that a “good equilibrium” is re-established. That means that I will ‘print’ whatever amount of money is needed so to make up for the drop in velocity we have seen. I will not stop the expansion of the money base before market participants again forecasts nominal GDP to have returned to it’s old trend path. Thereafter I will conduct monetary policy in such a fashion so NGDP is maintained on a 5% growth path.”

Lets assume that this new central bank governor is credible and market participants believe him. Lets call him Ben Volcker.

By issuing this statement the credible Ben Volcker will likely set in motion the following process:

1) Consumers who have been hoarding cash because they where expecting no and very slow growth in the nominal income will immediately reduce there holding of cash and increase private consumption.
2) Companies that have been hoarding cash will start investing – there is no reason to hoard cash when the economy will be growing again.
3) Banks will realise that there is no reason to continue aggressive deleveraging and they will expect much better returns on lending out money to companies and households. It certainly no longer will be paying off to put money into reserves with the central bank. Lending growth will accelerate as the “money multiplier” increases sharply.
4) Investors in the stock market knows that in the long run stock prices track nominal GDP so a promise of a sharp increase in NGDP will make stocks much more attractive. Furthermore, with a 5% path growth rule for NGDP investors will expect a much less volatile earnings and dividend flow from companies. That will reduce the “risk premium” on equities, which further will push up stock prices. With higher stock prices companies will invest more and consumers will consume more.
5) The promise of loser monetary policy also means that the supply of money will increase relative to the demand for money. This effectively will lead to a sharp sell-off in the country’s currency. This obviously will improve the competitiveness of the country and spark export growth.

These are five channels and I did not mention interest rates yet…and there is a reason for that. Interest rates will INCREASE and so will bond yields as market participant start to price in higher inflation in the transition period in which we go from a “bad equilibrium” to a “good equilibrium”.

Hence, there is no reason for the New Keynesian interest rate “fetish” – we got at least five other more powerful channels by which monetary policy works.

Monetary transmission mechanism with a credible NGDP level target

Ben Volcker has now with his announcement brought back the economy to a “good equilibrium”. In the process he might have needed initially to increase the money base to convince economic agents that he meant business. However, once credibility is established concerning the new NGDP level target rule Ben Volcker just needs to look serious and credible and then expectations and the market will take care of the rest.

Imagine the following situation. A positive shock increase the velocity of money and with a fixed money supply this pushed NGDP above it target path. What happens?

1) Consumers realise that Ben Volcker will tighten monetary policy and slow NGDP growth. With the expectation of lower income growth consumers tighten their belts and private consumption growth slows.
2) Investors also see NGDP growth slowing so they scale back investments.
3) With the outlook for slower growth in NGDP banks scale back their lending and increase their reserves.
4) Stock prices start to drop as expectations for earnings growth is scaled back (remember NGDP growth and earnings growth is strongly correlated). This slows private consumption growth and investment growth.
5) With expectations of a tightening of monetary conditions players in the currency market send the currency strong. This led to a worsening of the country’s competitiveness and to weaker export growth.
6) Interest rates and bond yields DROP on the expectations of tighter monetary policy.

All this happens without Ben Volcker doing anything with the money base. He is just sitting around repeating his dogma: “The central bank will control the money base in such a fashion that economic agents away expect NGDP to grow along the 5% path we already have announced.” By now he might as well been replaced by a computer…

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Recommended reading on the “old” monetarist transmission mechanism

Milton Friedman: “Milton Friedman’s Monetary Framework: A Debate with His Critics”
Karl Brunner and Allan Meltzer: “Money and the Economy: Issues in Monetary Analysis”

For a similar discussion to mine with special focus on the Paradox of Thrieft see the following posts from some of our Market Monetarist friends:

Josh Hendrickson
David Beckworth
Bill Woolsey
Nick Rowe

And finally from Scott Sumner on the differences between New Keynesian and Market Monetarist thinking.

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Update: Scott Sumner has a interesting comment on central banking “language” and “interest rates”.

Daylight saving time and NGDP targeting

Today I got up one hour later than normal. The reason is the same as for most other Europeans this morning – the last Sunday of October – we move our clocks back one hour due to the end of Daylight saving time (summertime).

That reminded me of Milton Friedman’s so-called Daylight saving argument for floating exchange rates. According to Friedman, the argument in favour of flexible exchange rates is in many ways the same as that for summer time. Instead of changing the clocks to summer time, everyone could instead “just” change their behaviour: meet an hour later at work, change programme times on the TV, let buses and trains run an hour later, etc. The reason we do not do this is precisely because it is easier and more practical to put clocks an hour forward than to change everyone’s behaviour at the same time. It is the same with exchange rates, one can either change countless prices or change just one – the exchange rate.

There is a similar argument in favour of NGDP level targeting. Lets illustrate it with the equation of exchange.

M*V=P*Y

P*Y is of course the same as NGDP the equation of exchange can also be written as

M*V=NGDP

What Market Monetarists are arguing is that if we hold NGDP constant (or it grows along a constant path) then any shock to velocity (V) should be counteracted by an increase or decrease in the money supply (M).

Obviously one could just keep M constant, but then any shock to V would feed directly through to NGDP, but NGDP is not “one number” – it is in fact made up of countless goods and prices. So an “accommodated” shock to V in fact necessitates changing numerous prices (and volumes for the matter). By having a NGDP level target the money supply will do the adjusting instead and no prices would have to change. Monetary policy would therefore by construction be neutral – as it would not influence relative prices and volumes in the economy.

So when you (re)read Friedman’s “The Case for Floating Exchange Rates” then try think instead of “The Case for NGDP Level Targeting” – it is really the same story.

See my posts on Friedman’s arguments for floating exchange rates:

Milton Friedman on exchange rate policy #1
Milton Friedman on exchange rate policy #2
Milton Friedman on exchange rate policy #3