How (un)stable is velocity?

Traditional monetarists used to consider money-velocity as rather stable and predictable. In the simple textbook version of monetarism V in MV=PY is often assumed to be constant. This of course is a caricature. Traditional monetarists like Milton Friedman, Karl Brunner or Allan Meltzer never claimed that velocity was constant, but rather that the money demand function is relatively stable and predictable.

Market Monetarists on the other hand would argue that velocity is less stable than traditional monetarists argued.  However, the difference between the two views is much smaller than it might look on the surface. The key to understanding this is the importance of expectations and money policy rules.

In my view we can not think of money demand – and hence V – without understanding monetary policy rules and expectations (Robert Lucas of course told us that long ago…). Therefore, the discussion of the stability of velocity is in some way similar to the discussion about whether monetary policy whether monetary policy works with long and variable leads or lags.

Therefore, V can said to be a function of the expectations of future growth in M and these expectations are determined by what monetary policy regime is in place. During the Great Moderation there was a clear inverse relationship between M and V. So when M increased above trend V would tend to drop and vice versa. The graph below shows this very clearly. I use the St. Louis Fed’s so-called MZM measure of the money supply.

This is not really surprising if you take into account that the Federal Reserve during this period de facto was targeting a growth path for nominal GDP (PY). Hence, a “overshoot” on money supply growth year one year would be counteracted the following year(s). That also mean that we should expect money demand to move in the direct opposite direction and this indeed what we saw during the Great Moderation. If the NGDP target is 100% credible the correlation between growth in M and growth in V to be exactly -1. (For more on the inverse relationship between M and V see here.)

The graph below shows the 3-year rolling correlation growth in M (MZM) and V in the US since 1960.

The graph very clearly illustrates changes in the credibility of US monetary policy and the monetary policy regimes of different periods. During the 1960 the correlation between M or V was highly unstable. This is during the Bretton Woods period, where the US effectively had a (quasi) fixed exchange rate. Hence, basically the growth of M and V was determined by the exchange rate policy.

However, in 1971 Nixon gave up the direct convertibility of gold to dollars and effectively killed the Bretton Woods system. The dollar was so to speak floated. This is very visible in the graph above. Around 1971 the (absolute) correlation between M and V becomes slightly more stable and significant higher. Hence, while the correlation between M and V was highly volatile during the 1960s and swung between +0 and -0.8 the correlation during the 1970s was more stable around -0.6, but still quite unstable compared to what followed during the Great Moderation.

The next regime change in US monetary policy happened in 1979 when Paul Volcker became Fed chairman. This is also highly visible in the graph. From 1979 we see a rather sharp increase in the (absolute) correlation between money supply growth and velocity growth.  Hence, from 1979 to 1983 the 3-year rolling correlation between MZM growth and velocity growth increased from around -0.6 to around -0.9. From 1983 and all through the rest of the Volcker-Greenspan period the correlation stayed around -0.8 to -0.9 indicating a very credible NGDP growth targeting regime. This is rather remarkable given the fact that the Fed never announced such a policy – nonetheless it seems pretty clear that money demand effectively behaved as if such a regime was in place.

It is also notable that there is a “pullback” in the correlation between M and V during the three recessions of the Great Moderation – 1990-91, 2001-2 and finally in 2008-9. This is rather clear indication of the monetary nature of these recessions.

The discussion above illustrates that the relationship between M and V to a very large degree is regime dependent. So while it might have been perfectly reasonable to assume that there was little correlation between M and V during the 1950s and 1960s that changed especially after Volcker defeated inflation and introduced a rule based monetary policy.

MV=PY is still the best tool for monetary analysis

So while V is far from as stable as traditional monetarists assumed the correlation between M and V is highly stable if monetary policy is credible and there is a clearly defined nominal target. Therefore MV=PY still provides the best tool for understanding monetary policy – and macroeconomics for that matter – as long as we never forget about the importance of monetary policy rules and expectations.

However, the discussion above also shows that we should be less worried about maintaining a stable rate of growth in M than traditional monetarists would argue. In fact the market mechanism will ensure a stable development in MV is the central bank has a credible target for PY. If we have a credible NGDP targeting regime then the correlation between M and V will be pretty close to -1.

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PS This discussion of course is highly relevant for what happened to US monetary policy in 2008, but the purpose of this post is to discuss the general mechanism rather than what happened in 2008. I would however notice that the correlation between growth in M and V dropped in 2008, but still remains fairly high. One should of course note here that this is the correlation between the growth of M and V rather than the level of M and V.

PPS In my discussion and graph above I have used MZM data rather than for example M2 data. The results are similar with M2, but slightly less clear. That to me indicates that MZM is a much better monetary indicator than M2. I am sure William Barnett would agree and maybe I would try to do the same exercise with his Divisia Money series.

Most people do “national accounting economics” – including most Austrians

Yesterday, I did a presentation about  monetary explanations for the Great Depression (See my paper here) at a conference hosted by the Danish Libertas Society. The theme of the conference was Austrian economics so we got of to an interesting start when I started my presentation with a bashing of Austrian business cycle theory – particularly the Rothbardian version (you know that has given me a headache recently).

The debate at the conference reminded me that most people – economists and non-economists – have a rather simple keynesian model in their heads or rather a simple national account model in their head.

We all the know the basic national account identity:

(1) Y=C+I+G+X-M

It is notable that most people are not clear about whether Y is nominal or real GDP. In the standard keynesian textbook model it is of course not important as prices (P) are assumed to be fixed and equal to one.

The fact that most people see the macroeconomics in this rather standard keynesian formulation means that they fail to understand the nominal character of recessions and hence nearly by construction they are unable to comprehend that the present crisis is a result of monetary policy mistake.

Whether austrian, keynesian or lay-person the assumption is that something happened on the righthand side of (1) and that caused Y to drop. The Austrians claim that we had an unsustainable boom in investments (I) caused by too low interest rates and that that boom ended in a unavoidable drop I. The keynesians (of the more traditional style) on the other hand claim that private consumption (C) and investments (I) is driven by animal spirits –  both in the boom and the bust.

What both keynesians and austrians completely fail to realise is the importance of money. The starting point of macroeconomic analysis should not be (1), but rather the equation of exchange:

(2) MV=PY

I have earlier argued that when we teach economics we should start out we money-free and friction-free micro economy. Then we should add money, move to aggregated prices and quantities and price rigidities. That is what we call macroeconomics.

If we can make people understand that the starting point of macroeconomic analysis should be (2) and not (1) then we can also convince them that the present recession (as all other recessions) is caused by a monetary contraction rather than drop in C or I. The drop in C and I are consequences rather the reasons for the recessions.

In this regard it is also important to note that Austrian Business Cycle Theory as formulated by Hayek or Rothbard basically is keynesian in nature in the sense that it is not really monetary theory. The starting point is that interest rates impact the capital structure and investments and that impacts Y – first as a boom and then as a bust. This is also why it is hard to convince Austrians that the present crisis is caused by tight money. (You could also choose to see Austrian business cycle theory as a growth theory that explain secular swings in real GDP, but that is not a business cycle theory).

Austrians and keynesians disagree on the policy response to the crisis. The Austrians want “liquidation” and the keynesians want to use fiscal policy (G) to fill the hole left empty by the drop in C and I in (1). This might actually also explain why “Austrians” often resort to quasi-moralist arguments against monetary or fiscal easing. In the Austrian model it would actually “work” if fiscal or monetary policy was eased, but that is politically unacceptable so you need to come up with some other objection. Ok, that is maybe not fair, but that is at least the feeling you get when you listen to populist part of the “Austrian movement” which is popular especially among commentators and young libertarians around the world – the Ron Paul crowd so to speak.

If people understood that our starting point should be (2) rather than (1) then people would also get a much better understanding of the monetary transmission mechanism. It is not about changes in interest rates to change C or I or changes in the exchange rate to change net exports (X-M). (Note of course in (1) M means imports and in (2) M means money). If we focus on (2) rather than (1) we will understand that a devaluation impact nominal demand by changes in M or V – it is really not about “competitiveness” – its about money.

So what we really want is a textbook that starts out with Arrow–Debreu in microeconomics and then move on (2) and macroeconomics. Imagine if economics students were not introduce to the mostly irrelevant national account identity (1) before they had a good understand on the equation of exchange (2)? Then I am pretty sure that we would not have these endless discussions about fiscal policy and most economists would then readily acknowledge that recessions are always and everywhere a monetary phenomenon.

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PS I am of course aware this partly is a caricature of both the Austrian and the keynesian position. New Keynesians are more clever than just relying on (1), but nonetheless fails really to grasp the importance of money. And then some modern day Austrians like Steve Horwitz fully appreciate that we should start out with (2) rather than (1). However, I am not really sure that I would consider Steve’s macro model to be a Austrian model. There is a lot more Leland Yeager and Clark Warburton in Steve’s model than there is Rothbard or Hayek. That by the way is no critique, but rather why I generally like Steve’s take on the world.

PPS Take a Scott Sumner’s discussion of Bank of England’s inflation. You will see Scott is struggling with the BoE’s research departments lack of understanding nominal vs real. Basically at the BoE they also start out with (1) rather than (2) and that is a central bank! No surprise they get monetary policy wrong…

Exchange rates and monetary policy – it’s not about competitiveness: Some Argentine lessons

I think Rob who is one my readers hit the nail on the head when he in a recent comment commented that one of the things that is clearly differentiating Market Monetarism from other schools is our view of the monetary transmission mechanism. In my reply to his comment I promised Rob to write more on the MM view of the monetary transmission mechanism. I hope this post will do exactly that.

It is well known that Market Monetarists see a significantly less central role for interest rates in the monetary transmission mechanism than New Keynesians (and traditional Keynesians) and Austrians. As traditional monetarists we believe that monetary policy works through numerous channels and that the interest rate channel is just one such channel (See here for a overview of some of these channels here).

A channel by which monetary policy also works is the exchange rate channel. It is well recognised by most economists that a weakening of a country’s currency can boost the country’s nominal GDP (NGDP) – even though most economists would focus on real GDP and inflation rather than at NGDP. However, in my view the general perception about how a weakening the currency impacts the economy is often extremely simplified.

The “normal” story about the exchange rate-transmission mechanism is that a weakening of the currency will lead to an improvement of the country’s competitiveness (as it – rightly – is assumed that prices and wages are sticky) and that will lead to an increase in exports and a decrease in imports and hence increase net exports and in traditional keynesian fashion this will in real GDP (and NGDP). I do not disagree that this is one way that an exchange rate depreciation (or devaluation) can impact RGDP and NGDP. However, in my view the competitiveness channel is far from the most important channel.

I would point to two key effects of a devaluation of a currency. One channel impacts the money supply (M) and the other the velocity of money (V). As we know MV=PY=NGDP this should also make it clear that exchange rates changes can impact NGDP via M or V.

Lets start out in a economy where NGDP is depressed and expectations about the future growth of NGDP is subdued. This could be Japan in the late 1990s or Argentina in 2001 – or Greece today for that matter.

If the central bank today announces that it has devalued the country’s currency by 50% then that would have numerous impacts on expectations. First of all, inflation expectations would increase dramatically (if the announcement is unexpected) as higher import prices likely will be push up inflation, but also because – and more important – the expectation to the future path of NGDP would change and the expectations for money supply growth would change. Take Argentina in 2001. In 2001 the Argentinian central bank was dramatically tightening monetary conditions to maintain the pegged peso rate against the US dollar. This send a clear signal that the authorities was willing to accept a collapse in NGDP to maintain the currency board. Naturally that lead consumers and investors to expect a further collapse in NGDP – expectations basically became deflationary.  However, once the the peg was given up inflation and NGDP expectations spiked. With the peso collapsing the demand for (peso) cash dropped dramatically – hence money demand dropped, which of course in the equation of exchange is the same as an increase in money-velocity. With V spiking and assuming (to begin with) that  the money supply is unchanged NGDP should by definition increase as much as the increase in V. This is the velocity-effect of a devaluation. In the case of Argentina it should of course be noted that the devaluation was not unexpected so velocity started to increase prior to the devaluation and the expectations of a devaluation grew.

Second, in the case of Argentina where the authorities basically “outsourced” the money policy to the Federal Reserve by pegging the peso the dollar. Hence, the Argentine central bank could not independently increase the money supply without giving up the peg. In fact in 2001 there was a massive currency outflow, which naturally lead to a sharp drop in the Argentine FX reserve. In a fixed exchange rate regime it follows that any drop in the foreign currency reserve must lead to an equal drop in the money base. This is exactly what happened in Argentina. However, once the peg was given up the central bank was free to increase the money base. With M increasing (and V increasing as argued above) NGDP would increase further. This is the money supply-effect of a devaluation.

The very strong correlation between Argentine M2 and NGDP can be seen in the graph below (log-scale Index).

I believe that the combined impact of velocity and money supply effects empirically are much stronger than the competitiveness effect devaluation – especially for countries in a deflationary or quasi-deflationary situation like Argentina was in in 2001. This is also strongly confirmed by what happened in Argentina from 2002 and until 2005-7.

This is from Mark Weisbrot’s and Luis Sandoval’s 2007-paper on “Argentina’s economic recovery”:

“However, relatively little of Argentina’s growth over the last five years (2002-2007) is a result of exports or of the favorable prices of Argentina’s exports on world markets. This must be emphasized because the contrary is widely believed, and this mistaken assumption has often been used to dismiss the success or importance of the recovery, or to cast it as an unsustainable “commodity export boom…

During this period (The first six months following the devaluation in 2002) exports grew at a 6.7 percent annual rate and accounted for 71.3 percent of GDP growth. Imports dropped by more than 28 percent and therefore accounted for 167.8 percent of GDP growth during this period. Thus net exports (exports minus imports) accounted for 239.1 percent of GDP growth during the first six months of the recovery. This was countered mainly by declining consumption, with private consumption falling at a 5.0 percent annual rate.

But exports did not play a major role in the rest of the recovery after the first six months. The next phase of the recovery, from the third quarter of 2002 to the second quarter of 2004, was driven by private consumption and investment, with investment growing at a 41.1 percent annual rate during this period. Growth during the third phase of the recovery – the three years ending with the second half of this year – was also driven mainly by private consumption and investment… However, in this phase exports did contribute more than in the previous period, accounting for about 16.2 percent of growth; although imports grew faster, resulting in a negative contribution for net exports. Over the entire recovery through the first half of this year, exports accounted for about 13.6 percent of economic growth, and net exports (exports minus imports) contributed a negative 10.9 percent.

The economy reached its pre-recession level of real GDP in the first quarter of 2005. As of the second quarter this year, GDP was 20.8 percent higher than this previous peak. Since the beginning of the recovery, real (inflation-adjusted) GDP has grown by 50.9 percent, averaging 8.2 percent annually. All this is worth noting partly because Argentina’s rapid expansion is still sometimes dismissed as little more than a rebound from a deep recession.

…the fastest growing sectors of the economy were construction, which increased by 162.7 percent during the recovery; transport, storage and communications (73.4 percent); manufacturing (64.4 percent); and wholesale and retail trade and repair services (62.7 percent).

The impact of this rapid and sustained growth can be seen in the labor market and in household poverty rates… Unemployment fell from 21.5 percent in the first half of 2002 to 9.6 percent for the first half of 2007. The employment-to-population ratio rose from 32.8 percent to 43.4 percent during the same period. And the household poverty rate fell from 41.4 percent in the first half of 2002 to 16.3 percent in the first half of 2007. These are very large changes in unemployment, employment, and poverty rates.”

Hence, the Argentine example clearly confirms the significant importance of monetary effects in the transmission of a devaluation to NGDP (and RGDP for that matter) and at the same time shows that the competitiveness effect is rather unimportant in the big picture.

There are other example out there (there are in fact many…). The US recovery after Roosevelt went of the gold standard in 1933 is exactly the same story. It was not an explosion in exports that sparked the sharp recovery in the US economy in the summer of 1933, but rather the massive monetary easing that resulted from the increase in M and V. This lesson obviously is important when we today are debate whether for example Greece would benefit from leaving the euro area or whether one or another country should maintain a pegged exchange rate regime.

A bit on Danish 1970s FX policy

In my home country of Denmark it is often noted that the numerous devaluations of the Danish krone in the 1970s completely failed to do anything good for the Danish economy and that that proves that devaluations are bad under all circumstances. The Danish example, however, exactly illustrate the problem with the “traditional” perspective on devaluations. Had Danish policy makers instead had an monetary approach to exchange rate policy in 1970s then the policies that would have been implemented would have been completely different.

Denmark – as many other European countries – was struggling with stagflation in the 1970s – both inflation and unemployment was high. Any monetarist would tell you (as Friedman did) that this was a result of a negative supply shock (and general structural problems) combined with overly loose monetary policy. The Danish government by devaluating the krone (again and again…) tried to improve competitiveness and thereby bring down unemployment. However, the high level of unemployment was not due to lack of demand, but rather due to supply side problems. The Danish economy was not in a deflationary trap, but rather in a stagflationary trap. That is the reason the devaluations did not “work” – well it worked perfectly well in terms of increasing inflation, but it did not bring down unemployment as the problem was not lack of demand (contrary to what is the case most places in Europea and the US today).

Conclusion – it’s not about competitiveness

So to conclude, the most important channels of exchange rate policy is monetary – the velocity effect and the money supply – the competitiveness effect is nearly as irrelevant as interest rates is. Countries that suffer from too tight monetary policy can ease monetary policy by announcing a credible devaluation or by letting the currency float. Argentina is a clear example of that. Countries that suffer from supply side problems – like Denmark in 1970s – can not solve the fundamental problems by devaluation.

PS the discussion above is not an endorsement of general economic policy in Argentina after 2001, but only meant as an illustration of the exchange rate channel for monetary policy. Neither is it an recommendation concerning what country XYZ should should do in terms of monetary and exchange rate policy today.

PPS Obviously Scott would remind us that the above discussion is just a variation of what Lars E. O. Svensson is telling us about the fool proof way out of a liquidity trap…

Update – some related posts:

The Chuck Norris effect, Swiss lessons and a (not so) crazy idea
Repeating a (not so) crazy idea – or if Chuck Norris was ECB chief
Argentine lessons for Greece

Are we overly focused on nominal issues?

Here is Trevor Adcock in answer to my previous post on “Regime Uncertainty”:

“Real regime uncertainty could also cause a recession if the uncertainty was over policies that affect prices and wages. The New Deal policies that distorted prices and wages directly contributed about as much to the Great Depression as policies that affected them indirectly through nominal GDP shocks. I sometimes feel that Market Monetarists focus too much on the left side of the equation of exchange and not enough on the right side.”

Trevor surely brings up a valid concern. Sometimes it seem like all of us Market Monetarist bloggers run around with our hammer and scream “If just the central banks would target the NGDP then everything would be fine”. We so to speak spend a lot (all?) of our time talking about MV in MV=PY and there might be real worry that people think that we underestimate other problems.

Is that because we do not think that there are structural problems in the US and European economies? Certainly not. I think most of us think that both the US and the European economies face very serious structural challenges and that the structural problems clearly hamper long-term real GDP growth. In fact I think most of us are much more concerned about these issues than mainstream economists – particularly mainstream European economists. After all we are all Free Market oriented (that’s an understatement) economists.

However, I believe that the present crisis both in the US and Europe is 90% nominal and 10% real. The crisis is a result of monetary policy mistakes. So yes, there are supply side problems both in the US and Europe but these problems did not cause nominal GDP to drop 10-15% below the pre-crisis trend level. This is why we are running around with our hammer and scream about NGDP level targeting all the time.

Furthermore, there is an important political-economic perspective on the discussion of nominal versus real problems. History has shown than when misguided monetary policies create problems then opt for interventionist policies to fix these problems rather than by fixing the nominal problems. Just think about NIRA and Smoot-Hawley in the US during the Great Depression or capital controls in France, Austria and Germany in 1930s. Today European policy makers are trying to “fix” the problems with highly damaging proposals for a Tobin tax, a ban on short-selling of stocks, legal attacks on rating agencies etc. No European policy makers (other than a few extreme leftists) were advocating these ideas prior to the crisis. Said in another way the monetary induced problems have led policy makers to come up with high damaging proposals that will reduce long-term real growth and do little or nothing to solve the problems facing the US and European economies at the moment. Milton Friedman’s case for floating exchange rates was to a large extent build on this kind of argument.

In my view some libertarian and conservative economists particular in the US is overplaying the “supply side problems”-card and by doing so actually discredit their own reform proposals. Many US Free Market economists for example have argued that the Obama administration’s proposals for healthcare reform played a key role in postponing the recovering in the US economy. Sorry guys that just comes across as a partisan argument rather than a argument based on sound economic reasoning. And note I am not endorsing Obama’s proposals – I just don’t think that it had any major impact on the speed of the recovery in the US economy. I am no fan of socialized medicine, but the issue is largely irrelevant for the present crisis. When the Clinton administration in the 1990s had proposals that was a lot more interventionist than what the Obama administration has suggested it did not led to a drop in economic activity in the US. And why not? Well, at that time the Federal Reserve was doing its job and kept NGDP growth on track (there comes the hammer again…).

We could of course spend more time on criticising these damaging policy proposals. We could also talk about the massive demographic challenges facing many Europe economies or talking about the massive burden on the economy from high taxes. But just because Milton Friedman focused most of his research on monetary issues I don’t think that anybody would argue that he did not care about supply issues. Market Monetarists are no different than uncle Milt in that regard.

PS see also my related post Monetary policy can’t fix all problems.

Guest Blog: The Two Fundamental Welfare Principles of Monetary Economics (By David Eagle)

I am extremely happy that David Eagle is continuing his series of guest blogs on my blog.

I strongly believe that David’s ideas are truly revolutionary and anybody who takes monetary policy and monetary theory serious should study  these ideas carefully. In this blog David presents what he has termed the “Two Fundamental Welfare Principles of Monetary Economics” as an clear alternative to the ad hoc loss functions being used in most of the New Keynesian monetary literature.

To me David Eagle here provides the clear microeconomic and welfare economic foundation for Market Monetarism. David’s thinking and ideas have a lot in common with George Selgin’s view of monetary theory – particularly in “Less than zero” (despite their clear methodological differences – David embraces math while George use verbal logic). Anybody that reads and understands David’s and George’s research will forever abandon the idea of a “Taylor function” and New Keynesian loss functions.

Enjoy this long, but very, very important blog post.

Lars Christensen

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Guest Blog: The Two Fundamental Welfare Principles of Monetary Economics

by David Eagle

Good Inflation vs. Bad Inflation

At one time, doctors considered all cholesterol as bad.  Now they talk about good cholesterol and bad cholesterol.  Today, most economists considered all inflation uncertainty as bad, at least all core inflation uncertainty.  However, some economists including George Selgin (2002), Evan Koenig (2011), Dale Domian, and myself (and probably most of the market monetarists) believe that while aggregate-demand-caused inflation uncertainty is bad, aggregate-supply-caused inflation or deflation actually improves the efficiency of our economies.  Through inflation or deflation, nominal contracts under Nominal GDP (NGDP) targeting naturally provide the appropriate real-GDP risk sharing between borrowers and lenders, between workers and employers, and more generally between the payers and receivers of any prearranged nominal payment.  Inflation targeting (IT), price-level targeting (PLT), and conventional inflation indexing actually interfere with the natural risk sharing inherent in nominal contracts.

I am not the first economist to think this way as George Selgin (2002, p. 42) reports that “Samuel Bailey (1837, pp. 115-18) made much the same point.”  Also, the wage indexation literature that originated in the 1970s, makes the distinction between demand-induced inflation shocks and supply-induced inflation shocks, although that literature did not address the issue of risk sharing.

The Macroeconomic Ad Hoc Loss Function vs. Parerto Efficiency

The predominant view of most macroeconomists and monetary economists is that all inflation uncertainty is bad regardless the cause.  This view is reflected in the ad hoc loss function that forms the central foundation for conventional macroeconomic and monetary theory.  This loss function is often expressed as a weighted sum of the variances of (i) deviations of inflation from its target and (ii) output gap.  Macro/monetary economists using this loss function give the impression that their analyses are “scientific” because they often use control theory to minimize this function.  Nevertheless, as Sargent and Wallace (1975) noted, the form of this loss function is ad hoc; it is just assumed by the economist making the analysis.

I do not agree with this loss function and hence I am at odds with the vast majority of the macro/monetary economists.  However, I have neoclassical microfoundations on my side – our side when we include Selgin, Bailey, Koenig, Domian, and many of the market monetarists.  This ad hoc social loss function used as the basis for much of macroeconomic and monetary theory is basically the negative of an ad hoc social utility function.  The microeconomic profession has long viewed the Pareto criterion as vastly superior to and more “scientific” than ad hoc social utility functions that are based on the biased preconceptions of economists.  By applying the Pareto criterion instead of a loss function, Dale Domian and I found what I now call, “The Two Fundamental Welfare Principles of Monetary Economics.”  My hope is that these Fundamental Principles will in time supplant the standard ad hoc loss function approach to macro/monetary economics.

These Pareto-theoretic principles support what George Selgin (p. 42) stated in 2002 and what Samuel Bailey (pp. 115-18) stated in 1837.  Some economists have dismissed Selgin’s and Bailey’s arguments as “unscientific.”  No longer can they legitimately do so.  The rigorous application of neoclassical microeconomics and the Pareto criterion give the “scientific” support for Selgin’s and Bailey’s positions.  The standard ad-hoc-loss-function approach in macro- and monetary economics, on the other hand, is based on pulling this ad hoc loss function out of thin air without any “scientific” microfoundations basis.

Macroeconomists and monetary economists have applied the Pareto criterion to models involving representative consumers.  However, representative consumers miss the important ramifications of monetary policy on diverse consumers.  In particular, models of representative consumers miss (i) the well-known distributional effect that borrowers and lenders are affected differently when the price level differs from their expectations, and (ii) the Pareto implications about how different individuals should share in changes in RGDP.

The Two Direct Determinants of the Price Level

Remember the equation of exchange (also called the “quantity equation), which says that MV=N=PY where M is the money supply, V is income velocity, N is nominal aggregate spending as measured by nominal GDP, P is the price level, and Y is aggregate supply as measured by real GDP.  Focusing on the N=PY part of this equation and solving for P, we get:

(1) P=N/Y

This shows there are two and only two direct determinants of the price level:

(i)             nominal aggregate spending as measured by nominal GDP, and

(ii)           aggregate supply as measured by real GDP.

This also means that these are the two and only two direct determinants of inflation.

The Two Fundamental Welfare Principles of Monetary Economics

When computing partial derivatives in calculus, we treat one variable as constant while we vary the other variable.  Doing just that with respect to the direct determinants of the price level leads us to The Two Fundamental Welfare Principles of Monetary Economics:

Principle #1:    When all individuals are risk averse and RGDP remains the same, Pareto efficiency requires that each individual’s consumption be unaffected by the level of NGDP.

Principle #2:    For an individual with average relative risk aversion, Pareto efficiency requires that individual’s consumption be proportional to RGDP.[1]

Dale Domian and I (2005) proved these two principles for a simple, pure-exchange economy without storage, although we believe the essence of these Principles go well beyond pure-exchange economies and apply to our actual economies.

My intention in this blog is not to present rigorous mathematical proofs for these principles.  These proofs are in Eagle and Domian (2005).  Instead, this blog presents these principles, discusses the intuition behind the principles, and gives examples applying the principles.

Applying the First Principle to Nominal Loans:

I begin by applying the First Principle to borrowers and lenders; this application will give the sense of the logic behind the First Principle.  Assume the typical nominal loan arrangement where the borrower has previously agreed to pay a nominal loan payment to the lender at some future date.  If NGDP at this future date exceeds its expected value whereas RGDP is as expected, then the price level must exceed its expected level because P=N/Y.  Since the price level exceeds its expected level, the real value of the loan payment will be lower than expected, which will make the borrower better off and the lender worse off.  On the other hand, if NGDP at this future date is less than its expected value when RGDP remains as expected, then the price level will be less than expected, and the real value of the loan payment will be higher than expected, making the borrower worse off and the lender better off.  A priori both the borrower and the lender would be better off without this price-level risk.  Hence, a Pareto improvement can be made by eliminating this price-level risk.

One way to eliminate this price-level risk is for the central bank to target the price level, which if successful will eliminate the price-level risk; however, doing so will interfere will the Second Principle as we will explain later.  A second way to eliminate this price-level risk when RGDP stays the same (which is when the First Principle applies), is for the central bank to target NGDP; as long as both NGDP and RGDP are as expected, the price level will also be as expected, i.e., no price-level risk..

Inflation indexing is still another way to eliminate this price-level risk.  However, conventional inflation indexing will also interfere with the Second Principle as we will soon learn.

That borrowers gain (lose) and lenders lose (gain) when the price level exceeds (fall short of) its expectations is well known.  However, economists usually refer to this as “inflation risk.” Technically, it is not inflation risk; it is price-level risk, which is especially relevant when we are comparing inflation targeting (IT) with price-level targeting (PLT).

An additional clarification that the First Principle makes clear concerning this price-level risk faced by borrowers and lenders is that risk only applies as long as RGDP stays the same.  When RGDP changes, the Second Principle applies.

Applying the Second Principle to Nominal Loans under IT, PLT, and NT:

The Second Principle is really what differentiates Dale Domian’s and my position and the positions of Bailey, Selgin, and Koenig from the conventional macroeconomic and monetary views.  Nevertheless, the second principle is really fairly easy to understand.  Aggregate consumption equals RGDP in a pure exchange economy without storage, capital, or government.  Hence, when RGDP falls by 1%, aggregate consumption must also fall by 1%.  If the total population has not changed, then average consumption must fall by 1% as well.  If there is a consumer A whose consumption falls by less than 1%, there must be another consumer B whose consumption falls by more than 1%.  While that could be Pareto justified if A has more relative risk aversion than does B, when both A and B have the same level of relative risk aversion, their Pareto-efficient consumption must fall by the same percent.  In particular, when RGDP falls by 1%, then the consumption level of anyone with average relative risk aversion should fall by 1%.  (See Eagle and Domian, 2005, and Eagle and Christensen, 2012, for the basis of these last two statements.)

My presentation of the Second Principle is such that it focuses on the average consumer, a consumer with average relative risk aversion.  My belief is that monetary policy should do what is optimal for consumers with average relative risk aversions rather than for the central bank to second guess how the relative-risk-aversion coefficients of different groups (such as borrowers and lenders) compare to the average relative risk aversion.

Let us now apply the Second Principle to borrowers and lenders where we assume that both the borrowers and the lenders have average relative risk aversion.  (By the way “relative risk aversion” is a technical economic term invented Kenneth Arrow, 1957, and John Pratt, 1964.)  Let us also assume that the real net incomes of both the borrower and the lender other than the loan payment are proportional to RGDP.  Please note that this assumption really must hold on average since RGDP is real income.  Hence, average real income = RGDP/m where m is the number of households, which means average real income is proportional to RGDP by definition (the proportion is 1/m).

The Second Principle says that since both the borrower and lender have average relative risk aversion, Pareto efficiency requires that both of their consumption levels must be proportional to RGDP.  When their other real net incomes are proportional to RGDP, their consumption levels can be proportional to RGDP only if the real value of their nominal loan payment is also proportional to RGDP.

However, assume the central bank successfully targets either inflation or the price level so that the price level at the time of this loan payment is as expected no matter what happens to RGDP.  Then the real value of this loan payment will be constant no matter what happens to RGDP.  That would mean the lenders will be guaranteed this real value of the loan payment no matter what happens to RGDP, and the borrowers will have to pay that constant real value even though their other net real incomes have declined when RGDP declined.  Under successful IT or PLT, borrowers absorb the RGDP risk so that the lenders don’t have to absorb any RGDP risk.  This unbalanced exposure to RGDP risk is Pareto inefficient when both borrowers and lenders have average relative risk aversion as the Second Principle states.

Since IT and PLT violate the Second Principle, we need to search for an alternative targeting regime that will automatically and proportionately adjust the real value of a nominal loan payment when RGDP changes?  Remember that the real value of the nominal loan payment is xt=Xt/P.  Replace P with N/Y to get xt=(Xt/Nt)Yt, which means the proportion of xt to Yt equals Xt/Nt.  When Xt is a fixed nominal payment, the only one way for the proportion Xt/Nt to equal a constant is for Nt to be a known in advance.  That will only happen under successful NGDP targeting.

What this has shown is that the proportionality of the real value of the loan payment, which is needed for the Pareto-efficient sharing of RGDP risk for people with average relative risk aversion, happens naturally with nominal fixed-payment loans under successful NGDP targeting.  When RGDP decreases (increases) while NGDP remains as expected by successful NGDP targeting, the price level increases (decreases), which decreases (increases) the real value of the nominal payment by the same percentage by which RGDP decreases (increases).

The natural ability of nominal contracts (under successful NGDP targeting) to appropriately distribute the RGDP risk for people with average relative risk aversion pertains not just to nominal loan contracts, but to any prearranged nominal contract including nominal wage contracts.  However, inflation targeting and price-level targeting will circumvent the nominal contract’s ability to appropriate distribute this RGDP risk by making the real value constant rather than varying proportionately with RGDP.

Inflation Indexing and the Two Principles:

Earlier in this blog I discussed how conventional inflation indexing could eliminate that price-level risk when RGDP remains as expected, but NGDP drifts away from its expected value.  While that is true, conventional inflation indexing leads to violations in the Second Principle.  Consider an inflation indexed loan when the principal and hence the payment are adjusted for changes in the price level.  Basically, the payment of an inflation-indexed loan would have a constant real value no matter what, no matter what the value of NGDP and no matter what the value of RGDP.  While the “no matter what the value of NGDP” is good for the First Principle, the “no matter what the value of RGDP” is in violation of the Second Principle.

What is needed is a type of inflation indexing that complies with both Principles.  That is what Dale Domian’s and my “quasi-real indexing” does.  It adjusts for the aggregate-demand-caused inflation, but not to the aggregate-supply-caused inflation that is necessary for the Pareto-efficient distribution of RGDP among people with average relative risk aversion.

Previous Literature:

Up until now, I have just mentioned Bailey (1837) and Selgin (2002) without quoting them.  Now I will quote them.  Selgin (2002, p. 42) states, ““ …the absence of unexpected price-level changes” is “a requirement … for avoiding ‘windfall’ transfers of wealth from creditors to debtors or vice-versa.”  This “argument … is perfectly valid so long as aggregate productivity is unchanging. But if productivity is subject to random changes, the argument no longer applies.”  When RGDP increases causing the price level to fall, “Creditors will automatically enjoy a share of the improvements, while debtors will have no reason to complain: although the real value of the debtors’ obligations does rise, so does their real income.”

Also, Selgin (2002, p. 41) reports that “Samuel Bailey (1837, pp. 115-18) made much the same point.  Suppose … A lends £100 to B for one year, and that prices in the meantime unexpectedly fall 50 per cent. If the fall in prices is due to a decline in spending, A obtains a real advantage, while B suffers an equivalent loss. But if the fall in prices is due to a general improvement in productivity, … the enhanced real value of B’s repayment corresponds with the enhanced ease with which B and other members of the community are able to produce a given amount of real wealth. …Likewise, if the price level were … to rise unexpectedly because of a halving of productivity, ‘both A and B would lose nearly half the efficiency of their incomes’, but ‘this loss would arise from the diminution of productive power, and not from the transfer of any advantage from one to the other’.”

The wage indexation literature as founded by Grey and Fischer recognized the difference between unexpected inflation caused by aggregate-demand shocks and aggregate-supply shocks; the main conclusion of this literature is that when aggregate-supply shocks exist, partial rather than full inflation indexing should take place.  Fischer (1984) concluded that the ideal form of inflation indexing would be a scheme that would filter out the aggregate-demand-caused inflation but leave the aggregate-supply-caused inflation intact.  However, he stated that no such inflation indexing scheme had yet been derived, and it would probably be too complicated to be of any practical use.  Dale Domian and I published our quasi-real indexing (QRI) in 1995 and QRI is not that much more complicated than conventional inflation indexing.  Despite the wage indexation literature leading to these conclusions, the distinction between aggregate-demand-caused inflation and aggregate-supply-caused inflation has not been integrated into mainstream macroeconomic theory.  I hope this blog will help change that.

Conclusions:

As the wage indexation literature has realized, there are two types of inflation:  (i) aggregate-demand-caused inflation and (ii) aggregate-supply-caused inflation.  The aggregate-demand-caused inflation is bad inflation because it unnecessary imposes price-level risk on the parties of a prearranged nominal contract.  However, aggregate-supply-caused inflation is good in that that inflation is necessary for nominal contracts to naturally spread the RGDP risk between the parties of the contract.  Nominal GDP targeting tries to keep the bad aggregate-demand-caused unexpected inflation or deflation to a minimum, while letting the good aggregate-supply-caused inflation or deflation take place so that both parties in the nominal contract proportionately share in RGDP risk.  Inflation targeting (IT), price-level targeting (PLT), and conventional inflation indexing interfere with the natural ability of nominal contracts to Pareto efficiently distribute RGDP risk.  Quasi-real indexing, on the other hand, gets rid of the bad inflation while keeping the good inflation.

Note that successful price-level targeting and conventional inflation indexing basically have the same effect on the real value of loan payments.   As such, we can look at conventional inflation indexing as insurance against the central bank not meeting its price-level target.

Note that successfully NGDP targeting and quasi-real indexing have the same effect on the real value of loan payments.  As such quasi-real indexing should be looked at as being insurance against the central bank not meeting its NGDP target.

A couple of exercises some readers could do to get more familiar with the Two Fundamental Welfare Principles of Welfare Economics is to apply them to the mortgage borrowers in the U.S. and to the Greek government since the negative NGDP base drift that occurred in the U.S. and the Euro zone after 2007.  In a future blog I very likely present my own view on how these Principles apply in these cases.

References:

Arrow, K.J. (1965) “The theory of risk aversion” in Aspects of the Theory of Risk Bearing, by Yrjo Jahnssonin Saatio, Helsinki.

Bailey, Samuel (1837) “Money and Its Vicissitudes in Value” (London: Effingham Wilson).

Debreu, Gerard, (1959) “Theory of Value” (New York:  John Wiley & Sons, Inc.), Chapter 7.

Eagle, David & Dale Domian, (2005). “Quasi-Real Indexing– The Pareto-Efficient Solution to Inflation Indexing” Finance 0509017, EconWPA, http://ideas.repec.org/p/wpa/wuwpfi/0509017.html.

Eagle, David & Lars Christensen (2012). “Two Equations on the Pareto-Efficient Sharing of Real GDP Risk,” future URL: http://www.cbpa.ewu.edu/papers/Eq2RGDPrisk.pdf.

Sargent, Thomas and Neil Wallace (1975). “’Rational’ Expectations, the Optimal Monetary Instrument, and the Optimal Money Supply Rule”. Journal of Political Economy 83 (2): 241–254.

Selgin, George (2002), Less than Zero: The Case for a Falling Price Level in a Growing Economy. (London: Institute of Economic Affairs).

Koenig, Evan (2011). “Monetary Policy, Financial Stability, and the Distribution of Risk,” Federal Reserve Bank of Dallas Research Department Working Paper 1111.

Pratt, J. W., “Risk aversion in the small and in the large,” Econometrica 32, January–April 1964, 122–136.

© Copyright (2012) by David Eagle

 


[1] Technically, the Second Principle should replace “average relative risk aversion” with “average relative risk tolerance,” which is from a generalization and reinterpretation by Eagle and Christensen (2012) of the formula Koenig (2011) derived.

A method to decompose supply and demand inflation

It is a key Market Monetarist position that there is good and bad deflation and therefore also good and bad inflation. (For a discussion of this see Scott Sumner’s and David Beckworth’s posts here and here). Basically one can say that bad inflation/deflation is a result of demand shocks, while good inflation/deflation is a result of supply shocks. Demand inflation is determined by monetary policy, while supply inflation is independent of whatever happens to monetary policy.

The problem is that the only thing that normally can be observed is “headline” inflation, which of course mostly is a result of both supply shocks and changes in monetary policy. However, inspired by David Eagle’s work on Quasi-Real Indexing (QRI) I will here suggest a method to decompose monetary policy induced changes in consumer prices from supply shock driven changes in consumer prices. I use US data since 1960 to illustrate the method.

Eagle’s simple equation of exchange

David Eagle in a number of his papers QRI starts out with the equation of exchange:

(1) M*V=P*Y

Eagle rewrites this to what he calls a simple equation of exchange:

(2) N=P*Y where N=M*V

This can be rewritten to

(3) P=N/Y

(3) Shows that consumer prices (P) are determined by the relationship between nominal GDP (N), which is determined by monetary policy (M*V) and by supply factors (Y, real GDP).

We can rewrite as growth rates:

(4) p=n-y

Where p is US headline inflation, n is nominal GDP growth and y is real GDP growth.

Introducing supply shocks

If we assume that we can separate underlining trend growth in y from supply shocks then we can rewrite (4):

(5) p=n-(yp+yt)

Where yp is the permanent growth in productivity and yt is transitory (shocks) changes in productivity.

Defining demand and supply inflation

We can then use (5) to define demand inflation pd:

(6) pd=n- yp

And supply inflation, ps, can then be defined as

(7) ps=p-pd (so p= ps+pd)

Below is shown the decomposition of US inflation since 1960. In the calculation of demand inflation I have assumed a constant growth rate in yp around 3% y/y (or 0.7% q/q). More advanced methods could of course be used to estimate yp (which is unlikely to be constant over time), but it seems like the long-term growth rate of GDP has been pretty stable around 3% of the last couple of decade. Furthermore, slightly higher or lower trend growth in RGDP does not really change the overall results.

We can of course go back from growth rates to the level and define a price index for demand prices as a Quasi-Real Price Index (QRPI). This is the price index that the monetary authorities can control.

The graph illustrates the development in demand inflation and supply inflation. There graph reveals a lot of insights to US monetary policy – for example that the increase in inflation in the 1970s was driven by demand inflation and hence caused by the Federal Reserve rather than by an increase in oil prices. Second and most interesting from today’s perspective demand inflation already started to ease in 2006 and in 2008 we saw a historically sharp drop in the Quasi-Real Price Index. Hence, it is very clear from our measure of the Quasi-Real Price Index that US monetary policy turning strongly deflationary already in early 2008 – and before (!) the collapse of Lehman Brothers.

Lets target a 2% growth path for QRPI

It is clear that many people (including many economists) have a hard time comprehending NGDP level targeting. However, I am pretty certain that most people would agree that the central bank should target something it can actually directly influence. The Quasi-Real Price Index is just another modified price index (in the same way as for example core inflation) so why should the Federal Reserve not want to target a path level for QRPI with a growth path of 2%? (the clever reader will of course realise that will be exactly the same as a NGDP path level target of 5% – under an assumption of long term growth of RGDP of 3%).

In the coming days I will have a look at the QRPI and US monetary history since the 1960s through the lens of the decomposition of inflation between supply inflation and demand inflation.

Defining central bank credibility

In a comment to my previous post on QE and NGDP targeting Joseph Ward argues that the Federal Reserve has “relatively solid central bank credibility”. The question is of course how to define central bank credibility.

To me a central bank is credible if the markets (and the general public) expect the central bank to hit the targets it have. The problem of course for the Fed is that it does not have a target. That makes it pretty hard to say whether it is credible or not.

Another way of saying whether a central bank is credible or not is to look at the predictability of nominal variables: money suppy, velocity, nominal wages, prices, inflation, NGDP, the exchange rates etc. I am pretty sure that if you estimate of example simple AR-models for these variables you will see the error-term in the models has exploded since 2008. I must, however, say I am guessing here. but I am pretty sure I am right – maybe an econometrician out there would try to estimate it?

In the case of the ECB the collapse in credibility is pretty clear. The ECB used to have a two-pillar policy – targeting directly or indirectly M3 growth and inflation. Judging from market expectations for medium term inflation the credibility is not good – in fact it has never been this bad. Medium-term inflation expectations are well-below the 2% inflation target. In terms of M3 the ECB has normally targeted a reference rate around 4.5% y/y. The actual growth rate on M3 is much below this “target”.

HOWEVER, if the central banks were indeed so credible then the markets should fully believe any nominal target they would announce. So if the Fed is 100% credible and announce that it will increase NGDP by 15% over the coming two years then there should be no problem meeting this target – without printing more money. What would happen is the money-velocity would jump, which with an unchanged money supply would increase NGDP.

During the Great Moderation there was a very high degree of negative correlation between M and V growth in the US. This indicates in my view that markets expected the Fed to meet a NGDP “target” and in that sense monetary policy became endogenous – pretty much in the same way as in a Selgin-White Free Banking model.

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”

Friedman’s thermostat and why he obviously would support a NGDP target

In a recent comment Dan Alpert argues that Milton Friedman would be against NGDP targeting. I have the exact opposite view and I am increasingly convinced that Milton Friedman would be a strong supporter of NGDP targeting.

Ed Dolan as the same view as I have (I have stolen this from Scott Sumner):

“I see NGDP targeting as the natural heir to monetarist policy prescriptions of the 1960s and 70s…If we look at the textbook version of monetarism, the point is almost trivial. Textbook monetarism begins from the equation of exchange, MV=PQ, where M is money (M1, back in the day), V is velocity, P is the price level, Q is real GDP, and PQ is NGDP. Next it adds the simplifying assumption that velocity is constant. It follows that targeting a steady rate of money growth is identical to targeting a steady rate of NGDP growth.”

Dolan’s clear argument reminded me of Friedman’s paper from 2003 “The Fed’s Thermostat”.

Here is Friedman:

“To keep prices stable, the Fed must see to it that the quantity of money changes in such a way as to offset movements in velocity and output. Velocity is ordinarily very stable, fluctuating only mildly and rather randomly around a mild long-term trend from year to year. So long as that is the case, changes in prices (inflation or deflation) are dominated by what happens to the quantity of money per unit of output…since the mid ’80s, it (the Fed) has managed to control the money supply in such a way as to offset changes not only in output but also in velocity…The improvement in performance is all the more remarkable because velocity behaved atypically, rising sharply from 1990 to 1997 and then declining sharply — a veritable bubble in velocity. Velocity peaked in 1997 at nearly 20% above its trend value and then fell sharply, returning to its trend value in the second quarter of 2003.…The relatively low and stable inflation for this period …means that the Fed successfully offset both the decline in the demand for money (the rise in V) before 1973 and the subsequent increase in the demand for money. During the rise in velocity from 1988 to 1997, the Fed kept monetary growth down to 3.2% a year; during the subsequent decline in velocity, it boosted monetary growth to 7.5% a year.”

Hence, Friedman clearly acknowledges that when velocity is unstable the central bank should “offset” the changes in velocity. This is exactly the Market Monetarist view – as so clearly stated by Ed Dolan above.

So why did Friedman man not come out and support NGDP targeting? To my knowledge he never spoke out against NGDP targeting. To be frank I think he never thought of the righthand side of the equation of exchange – he was focused on the the instruments rather than on outcome in policy formulation. I am sure had he been asked today he would clearly had supported NGDP targeting.

The only difference I possibly could see between what Friedman would advocate and what Market Monetarists are arguing today is whether to target NGDP growth or a path for the NGDP level.

—-

PS I am not the first Market Monetarist to write about Friedman’s Thermostat – both Nick Rowe and David Beckworth have blogged about it before.

The inverse relationship between central banks’ credibility and the credibility of monetarism

A colleague of mine today said to me ”Lars, you must be happy that you can be a monetarist again”. (Yes, I am a Market Monetarists, but I consider that to be fully in line with fundamental monetarist thinking…)

So what did he mean? In the old days – prior to the Great Moderation monetarists would repeat Milton Friedman’s dictum that “inflation is always and everywhere a monetary phenomenon” and suddenly by the end of the 1970s and 1980s people that started to listen. All around the world central banks put in place policies to slow money supply growth and thereby bring down inflation. In the policy worked and inflation indeed started to come down around the world in the early 1980.

Central banks were gaining credibility as “inflation fighters” and Friedman was proven right – inflation is indeed always and everywhere a monetary phenomenon. However, then disaster stroke – not a disaster to the economy, but to the credibility of monetarism, which eventually led most central banks in the world to give up any focus on monetary aggregates. In fact it seemed like most central banks gave up any monetary analysis once inflation was brought under control. Even today most central banks seem oddly disinterested in monetary theory and monetary analysis.

The reason for the collapse of monetarist credibility was that the strong correlation, which was observed, between money supply growth and inflation (nominal GDP growth) in most of the post-World War II period broke down. Even when money supply growth accelerated inflation remained low. In time the relationship between money and inflation stopped being an issue and economic students around the world was told that yes, inflation is monetary phenomenon, but don’t think too much about it. Many young economists would learn think of the equation of exchange (MV=PY) some scepticism and as old superstition. In fact it is an identity in the same way as Y=C+I+G+X-M and there is no superstition or “old” theory in MV=PY.

Velocity became endogenous
To understand why the relationship between money supply growth and inflation (nominal GDP growth) broke down one has to take a look at the credibility of central banks.

But lets start out the equation of exchange (now in growth rates):

(1) m+v=p+y

Once central bankers had won credibility about ensure a certain low inflation rate (for example 2%) then the causality in (1) changed dramatically.

It used to be so that the m accelerated then it would fast be visible in higher p and y, while v was relatively constant. However, with central banks committed not to try to increase GDP growth (y) and ensuring low inflation – then it was given that central banks more or less started to target NGDP growth (p+y).

So with a credible central that always will deliver a fixed level of NGDP growth then the right hand side of (1) is fixed. Hence, any shock to m would be counteracted by a “shock” in the opposite direction to velocity (v). (This is by the way the same outcome that most theoretical models for a Free Banking system predict velocity would react in a world of a totally privatised money supply.) David Beckworth has some great graphs on the relationship between m and v in the US before and during the Great Moderation.

Assume that we have an implicit NGDP growth path target of 5%. Then with no growth in velocity then the money supply should also grow by 5% to ensure this. However, lets say that for some reason the money supply grow by 10%, but the “public” knows that the central bank will correct monetary policy in the following period to bring back down money to get NGDP back on the 5% growth path then money demand will adjust so that NGDP “automatically” is pushed back on trend.

So if the money supply growth “too fast” it will not impact the long-term expectation for NGDP as forward-looking economic agents know that the central bank will adjust monetary policy to bring if NGDP back on its 5% growth path.

So with a fixed NGDP growth path velocity becomes endogenous and any overshoot/undershoot in money supply growth is counteracted by a counter move in velocity, which ensures that NGDP is kept on the expected growth path. This in fact mean that the central banks really does not have to bother much about temporary “misses” on money supply growth as the market will ensure changes in velocity so that NGDP is brought back on trend. This, however, also means that the correlation between money and NGDP (and inflation) breaks down.

Hence, the collapse of the relation between money and NGDP (and inflation) is a direct consequence of the increased credibility of central banks around the world.

Hence, as central banks gained credibility monetarists lost it. However, since the outbreak of the Great Recession central banks have lost their credibility and there are indeed signs that the correlation between money supply growth and NGDP growth is re-emerging.

So yes, I am happy that people are again beginning to listen to monetarists (now in a improved version of Market Monetarism) – it is just sad that the reason once again like in the 1970s is the failure of central banks.

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