The Output Gap is no longer a sufficient statistic for inflationary pressure

One of the features of the latest OBR forecast is that they believe the economy is operating slightly above its sustainable level (a positive output gap), where the sustainable level is the level that would keep inflation constant. To see how startling that hypothesis is, here is the latest version of a chart I have probably posted more than any other since I started writing this blog.

It is UK GDP per head (source), which is a pretty good measure of average prosperity, and a trend line in red for 2.23% growth p.a. So from 1955 to 2007 prosperity grew at an average rate of almost two and a quarter percent each year. Since then it has increased at an annual rate of around 0.35%. And if the OBR are right, none of this is due to unutilised resources and lack of demand.

The shift in trend is just as clear if we look at output per worker. Some people try and rationalise this by saying that 2007 was a boom year, and so trend growth had really been falling long before the Global Financial Crisis (GFC). But the evidence does not support more than a slight downward shift in the growth trend before the GFC: the OBR estimate an output gap of 0.7% in 2006/7 and 1.8% in 2007/8.

I find it extraordinary that most economists still talk about the output gap after the GFC in the same way that it was talked about before the crisis: as a limit to how far and fast the economy can expand. To do that is in my view quite wrong. It ignores what I call the innovations gap: the difference between actual output and the level of output that firms could achieve if they started using the best technology available to them. Because there is currently a large innovations gap, firms are likely to meet additional demand not be raising prices but by investing in these more efficient techniques.

Before the GFC, we could ignore the innovation gap because it was relatively small. But since the crisis that gap for the UK and many other countries must have increased, because it is simply not plausible to assume that since the GFC technical progress has come to a virtual halt. Innovations may not have been increasing at the pre-GFC rate, but they cannot have almost stopped, which is the implicit assumption in the OBR’s analysis. Hence we have in the UK, and I suspect in many other countries, a subsrantial innovations gap which will prevent any excess demand leading to significant inflationary pressure. Some supporting evidence for this comes from the growing productivity divergence between leading firms and the rest.

Why have most firms not been investing in the most productive equipment and techniques since the GFC? I think the simple answer is fixed costs and demand. Investment projects almost always involve a large fixed cost element (disruption, retraining), and with static demand those fixed costs may exceed any efficiency gain. But in a normal recovery from a recession, where demand is growing rapidly, firms are happy to incur that fixed cost because they need to expand capacity anyway to meet growing demand. In a weak recovery, on the other hand, many firms may not need to expand capacity, with any modest increases in demand going to leading firms, firms that do invest in the latest technology. Hence the divergence noted above.

Exactly the same argument applies to the NAIRU: the level of unemployment at which inflation is constant. The NAIRU is almost certainly lower than most central banks think for a variety of reasons, but when it is approached I expected to see a pick up in investment and innovation more than a pick up in wage inflation. Investment and productivity growth go together, as a nice chart in the OBR’s latest forecast report shows (page 43).

A large innovation gap in the UK is being enhanced by Brexit. The more uncertain future demand is the more firms are likely to postpone productivity enhancing investment. It may be politically useful to delay creating a new customs union/SM for goods with the EU to try and keep the Conservative party together (as regular readers will know, I think this is inevitable because of the Irish border), but the uncertainty that delay creates just holds back UK growth. Just one more way in which both Brexit and more generally a Conservative government is an economically destructive project.

The existence of a large innovations gap, both in the UK and elsewhere, means that we need two things. First, we need a monetary policy that is very relaxed about raising interest rates. Second we need, in the UK and pretty well everywhere, a large increase in public sector investment. The first needs independent central banks to be less inflation averse and to stop treating the sustainable level of output as something which is independent of what they do. The second requires governments to stop being obsessed about deficits and instead to start investing in the future of all the people they govern.

Is a flexible labour market a problem for central bankers?

Recessions and milder economic downturns are typically a result of insufficient aggregate demand for goods. The only way to end them is to stimulate demand in some way. That may happen naturally, but it may also happen because monetary policymakers reduce interest rates. How do we know we have deficient aggregate demand? Because unemployment increases, as a lower demand for goods leads to layoffs and less new hires.

A question that is sometimes posed in macroeconomics is whether workers in a recession could ‘price themselves into jobs’ by cutting wages. In past recessions workers have been reluctant to do this. But suppose we had a more prolonged recession, because fiscal austerity had dampened the recovery, and over this more prolonged period wages had become less rigid. Then falling real wages could price workers into jobs, and reduce unemployment. [1]

This is not because falling real wages cure the problem of deficient aggregate. If anything lower real wages might reduce aggregate demand by more. But it is still possible that workers could price themselves into jobs, because firms might switch to more labour intensive production techniques, or fail to invest in new labour saving techniques. We would see output still depressed, but unemployment fall, employment rise and stagnant labour productivity. Much as we have done in the UK over the last few years.

It is important to understand that in these circumstances the problem of deficient demand is still there. Resources are still being wasted on a huge scale. Quite simply, we could all be much better off if demand could be stimulated. How would central bankers know whether this was the case or not?

Central bankers might say that they would still know there was inadequate demand because surveys would tell them that firms had excess capacity. That would undoubtedly be true in the immediate aftermath of the recession, but as time went on capital would depreciate and investment would remain low because firms were using more labour intensive techniques. The surveys would become as poor an indicator of deficient aggregate demand as the unemployment data.

What about all those measures of the output gap? Unfortunately they are either based on unemployment, surveys, or data smoothing devices. The last of these, because they smooth actual output data, simply say it is about time output has fully recovered. Or to put it another way, trend based measures effectively rule out the possibility of a prolonged period of deficient demand. [2] So collectively these output gap measures provide no additional information about demand deficiency.

The ultimate arbiter of whether there is demand deficiency is inflation. If demand is deficient, inflation will be below target. It is below target in most countries right now, including the US, Eurozone and Japan. (In the UK inflation is above target because of the Brexit depreciation, but wage inflation shows no sign of increasing.) So in these circumstances central bankers should realise that demand was deficient, and continue to do all they can to stimulate it.

But there is a danger that central bankers would look at unemployment, and look at the surveys of excess capacity, and look at estimates of the output gap, and conclude that we no longer have inadequate aggregate demand. In the US interest rates are rising, and there are those on the MPC that think the same should happen here. If demand deficiency is still a problem, this would be a huge and very costly mistake, the kind of mistake monetary policymakers should never ever make. [3] There is a fool proof way of avoiding that mistake, which is to keep stimulating demand until inflation rises above target.

One argument against this wait and see policy is that policymakers need to be ‘ahead of the curve’, to avoid abrupt increases in interest rates if inflation did start rising. Arguments like this treat the Great Recession as just a larger version of the recessions we have seen since WWII. But in these earlier recessions we did not have interest rates hitting their lower bound, and we did not have fiscal austerity just a year or two after the recession started. What we could be seeing instead is something more like the Great Depression, but with a more flexible labour market.

[1] Real wages could also be more flexible because the Great Recession allowed employers to increase job insecurity, which might both increase wage flexibility and reduce the NAIRU. Implicit in this account is that lower nominal wages did not get automatically passed on as lower prices. If they had, real wages would not fall. Why this failed to happen is interesting, but takes us beyond the scope of this post.

[2] They also often imply that the years immediately before the Great Recession were a large boom period, despite all the evidence that they were no such thing outside the Eurozone periphery

[3] J.W. Mason has recently argued that such a mistake is being made in the US in a detailed report.

The Output Gap and the Innovations Gap

A major objection to my suggestion that the UK is in an self-fulfilling expectations led recession is that measures of the output gap suggest that gap is near zero. What I want to argue here is that measures of the output gap ignore what I will call the innovations gap, and the innovations gap could indicate that demand expansion would not be inflationary.

The output gap is the difference between actual output and trend output, where trend output is the level of output at which inflation is stable. The OBR are the output gap kings. They have a composite measure, which Ben Chu shows here, but this is derived from many different measures, shown in the OBR’s latest forecast on page 36. The OBR also show (p38) that estimates produced by other organisations vary widely. Most measures of the output gap can be categorised into four kinds.

1. Time series filters. These, at their most simple, just smooth the data on actual output to produce the measure of trend output that is one half of the output gap. These have no economic content and therefore tell us almost nothing.
   
   
2. Production function estimates. These combine measures of the labour force with the capital stock to give potential output: the level of output that could be produced if all factors of production were fully utilised. The major problem with these measures is that they have no measure of technology: how much can be produced by capital and labour. What is generally done is to use time series methods to estimate this, which takes us back to the smoothing idea. As a result, measures produced by the IMF and OECD suggest the years before the recession were a huge boom, which is implausible given other evidence we have.
   
   
3. Labour market measures, like unemployment or participation. There are of course many problems in knowing what the non-inflationary level of these variables are.
   
   
4. Firm surveys. These ask questions like are you producing at normal levels of capacity utilisation. The answer you get right now is that firms are indeed working close to normal capacity.
   
   

With these definitions in mind, what we have to ask is do any of these measures tell us what we really want to know, which is would firms react to increases in demand by raising prices and wages. I want to argue that they may not after an economy has grown at rates well below previous trends for a while. The reason is that, in these circumstances, firms may know that their current production methods are outdated, too labour intensive and inefficient, but at current levels of demand it is not worth them investing in new techniques. However if demand did increase, rather than raise prices to choke off that new demand, it would be more profitable to investment in new equipment to meet that additional demand. An expansion in demand would not be inflationary because firms would not raise their prices. In addition, because these new techniques were labour saving, there would be no inflationary pressure in the labour market (although real wages would rise because productivity increased).

We can tell the following story about the UK economy. At the peak of the recession, unemployment was high and firms had spare capacity. All the output gap measures said the output gap was large. What would normally happen next is that output would start recovering rapidly at above trend rates of growth, leading to a pickup in investment and new techniques being embodied in new production. But that didn’t happen in the UK, mainly because austerity held back demand and interest rates couldn’t go negative. 

When demand did finally begin to expand at a modest rate in 2013, cautious firms decided to meet that additional demand not through new investment but by using existing spare capacity. During 2013 and 2014 employment increased and the output gap fell, but productivity was stagnant because most firms were not investing in new techniques. (The market leaders were, because being market leaders they were expanding more rapidly and investing. So as Martin Sandbu has discussed, the UK productivity puzzle is associated with the average firm, not leading firms.)

This meant that by 2015, unemployment had fallen to more normal levels, and firms no longer had spare capacity. All this had been achieved with stagnant productivity growth, because most firms had stopped investing in new innovations. It was not because those innovations had stopped being made. So the output gap had been replaced by an innovations gap, with most firms using out of date production techniques that are too labour intensive.

If this story is right, we have become locked in a self-fulfilling low growth trap. Firms will not invest because they see recent slow growth continuing. They are right, because policymakers, looking at the output gap rather than the innovation gap, are doing nothing to expand demand for fear of inflation, or worse still because of mistaken worries about government debt. I do not know if this story is right, but it seems to me that the cost in lost output if it is right is so great that it is foolish to ignore this possibility.   

The Eurozone Scandal

Imagine that it was revealed that 10% of the European Union budget (the money that goes to the EU centre to fund the common agricultural policy and other EU wide projects) had been found to be completely wasted as a result of actions by EU policymakers. By wasted I do not mean spent on things that maybe it should not have been spent on (rich farmers, inefficient farmers, infrastructure projects whose costs exceed benefits etc), but literally money that went up in smoke. Imagine the scandal. Heads would roll, and some might find themselves in jail.

10% of the EU budget is about 0.1% of EU GDP. Yet sums at least ten times that figure are currently being wasted in the Eurozone, as a result of actions by Eurozone policymakers. Here is the latest OECD assessment of output gaps across eleven Eurozone countries, for both 2013 (blue) and 2014 (red).

A negative output gap means that output could be the amount of the gap higher without raising inflation above target. Of course Greece is a nightmare, and things in the other PIIGS are really bad, but the output gap in the Netherlands is around 3%, in France over 2% in 2014, and even in Germany the output gap exceeds 1%. Estimating output gaps is an imprecise science, but gaps of at least this size are consistent with inflation well below target (currently 0.3%). So output could be at least 1% higher across the Eurozone with no ill effects. This is the equivalent of the entire EU budget going up in smoke.

Sometimes negative output gaps are the result of shocks which were not anticipated by policymakers (like the financial crisis). Sometimes they are engineered by policymakers to bring inflation down. It is unfortunate that these things happen, but they always have. However the output gaps we have in the Eurozone today are neither of these. Instead they have been created by policymakers for no good reason. That is why they can be called a scandal.

At this point you might think I’m being unfair. Surely this is all about tight fiscal policy required to bring down government debt. I agree that it is all about fiscal policy, and in particular the crazy fiscal rules imposed within the Eurozone. However where is the urgent need to bring down debt outside the periphery? The OECD estimate that the primary structural budget balance in the Eurozone will be a surplus at around 1% of GDP in 2014 compared to a deficit in the OECD as a whole of just over 1%. So even if you think that we need austerity to bring deficits down rapidly - which I do not - why should policymakers in the Eurozone be doing this so much more quickly than in the UK, US or Japan? To achieve this goal, they are wasting resources on a colossal scale.

If you think anything has changed as a result of Juncker’s ‘E315 bn’ investment plan, you should read this post from Frances Coppola. As she makes clear, there is not a penny of new EU money in this proposal. Instead money earmarked for existing projects is being used to provide insurance to private sector investment (which may or may not happen). There are so many issues with this kind of stimulus. Besides those raised by Frances, there is also the question of how to prevent firms simply getting insurance for schemes they would have undertaken anyway, and how exactly will the Commission select when to allocate its insurance. Those of a neoliberal persuasion who think government is bad at spending its money cannot feel any more comfortable with the government selecting what private sector projects to back. However a scheme like this will come as no surprise to someone like George Monbiot, who thinks states are increasingly being used to serve corporate ends. 

Equally embroiled in this scandal are those making monetary policy decisions at the ECB. Here I can simply defer to an excellent post by Ashoka Mody. In particular he points out why it is misleading to simply look at the ECB’s balance sheet as an indicator of the force of unconventional monetary policy. There is an important difference between creating money to bail out failing banks, as the ECB has done, and creating money to buy bonds to force down long term rates, which is Quantitative Easing (QE). He argues that the “ECB is set to remain—by far—the central bank with the tightest, most conservative monetary policy among the major central banks.” I thought I would quote the following paragraph in full, for reasons that will be clear to regular readers.

“Others play by the rules of the cognitive frame. Thus, despite the serious concerns with the June 5th measures—documented carefully by my Bruegel colleagues—journalists have no interest in asking ECB officials: “What exactly are we waiting for?” The financial markets have no interest in public policy: once the rules are set, they seek opportunities for short-term bets. On July 9th, the International Monetary Fund’s Executive Board somewhat incredulously concluded: “Directors welcomed the exceptional measures recently taken by the European Central Bank (ECB) to address low inflation and strengthen demand, as well as its intention to use further unconventional instruments if necessary.” Belatedly, on November 25th, the OECD became a lone official voice calling for more urgent steps.“

To those who say that QE, as operated by the BoE or Fed, would have limited effectiveness in the Eurozone, I have a lot of sympathy. However there is a relatively simple way of making QE much more effective and predictable, and that is for central banks to create money not to buy financial assets but to transfer directly to citizens, which Friedman called helicopter money. John Muellbauer calls this QE for the people. Conventional QE involves buying a large amount of assets with potential losses for the central bank (if the asset price falls) but uncertain effects on demand. Helicopter money involves small transfers with a certain loss to the central bank but much more predictable positive demand effects. [1]

As an institutional innovation, helicopter money has two major drawbacks in countries with their own central bank. [2] First, why innovate when you can implement exactly the same policy through existing means: in macroeconomic terms helicopter money is equivalent to QE plus tax cuts when you have inflation targeting. Second, a fiscal stimulus in the form of temporary additional government spending is likely to be more predictable in its impact than transfers or tax cuts, because you eliminate the uncertainty caused by how much of the transfer or tax cut will be spent.

But if countercyclical fiscal policy is effectively illegal in the Eurozone, these objections do not apply. QE for the people may have additional legal merits within the Eurozone. The ECB is constrained to some (uncertain) extent in its ability to buy government debt. But, as John Muellbauer suggests, mailing a cheque to every EZ citizen using electoral registers would seem to circumvent these legal difficulties.

One objection to the ECB embarking on ‘QE for the people’ is that it goes well beyond the remit of a central bank. [3] Yet the ECB appears to have no qualms on that score: besides routine references for the need for fiscal consolidation and ‘structural reform’, the letter discussed by Paul De Grauwe here shows the ECB requiring detailed changes to labour market regulations and institutions in Spain. So you have to ask why is it OK for the central bank to override the democratic process in this way, but giving money directly to the people is somehow beyond the pale.

If you think that mailing a cheque to every voter in the Eurozone as a solution to continuing recession sounds too good to be true, then you have just rediscovered why recessions caused by demand deficiency when inflation is below target are such a scandalous waste. It is a problem that can be easily solved, with lots of winners and no losers. The only reason that this is not obvious to more people is that we have created an institutional divorce between monetary and fiscal policy that obscures that truth. It was a divorce that did a reasonable job in steering the economy in normal times, and it might discourage fiscal profligacy when demand is strong, but since 2010 it has led to a scandalous paralysis in the Eurozone.  

  

[1] These losses are notional only, as the central bank is not in the business of making money. They matter only if they compromise the ability of the central bank to do its job of controlling inflation in the future. There are various ways that danger can be avoided, but my point here is that costs to the central bank can arise with any form of QE.

[2] Central banks routinely pass the profits they make (through seigniorage) to governments. So the innovation is that the central bank rather than the government decides how to disperse this money.  

[3] Another objection is that, because the ECB is free to define its own targets, changing the monetary policy framework to target the level of nominal GDP would be a better innovation. I agree this would be a useful innovation. I would argue that it would be better still to allow countercyclical fiscal policy, because only this can deal with country specific shocks. But if, for whatever reason, these changes are ruled out, then a helicopter drop should be implemented. If you are a market monetarist, think of it as an insurance policy.

    

The UK recovery and the pessimists’ refrain

In two recent posts I plotted UK GDP per person since 1950. What is remarkable to me about that time series is how well a simple trend tracks the data – until the current recession. In reality trend growth rates have probably moved around a bit, but the important point is that past recessions have essentially turned out to be temporary deviations from trend growth, rather than signaling fundamental shifts. In particular, following both the major recessions of the early 1980s and 1990s, we achieved recoveries that brought us back to something close to the level of output we could have achieved if there had been no recession.

There are two arguments that this time will be different: what I will call the pessimists’ refrain. The first is that we were fooling ourselves before the recession, because in reality we were ‘living beyond our means’. This argument suggests that output in 2007 was unsustainably high, so our trend line should be lower and flatter. The second is that since 2008/9 productivity has stalled because the financial system in the UK has been broken. I call these ‘refrains’, because they usually come with a repeated message: we should stop stimulating the economy, because if we try to get back the ground we lost, we will fail and instead generate inflation. (A third argument focuses on hysteresis effects of high unemployment, but this is more important for the US than the UK.)

Larry Summers has recently reminded us that there was something odd about the pre-recession period in a number of countries including the US and UK. Although inflation was reasonably stable, we had the kind of housing bubbles that we normally associate with booms. Now Summers argued that this indicated an underlying demand weakness: we could only get people to buy all the stuff we could produce by encouraging them to take out an unusual amount of debt. There is an alternative explanation, which is that - despite appearances - there was a boom before the recession. We were, in 2007, living beyond our means. 

This idea is not the view of a small minority. Organisations like the OECD and IMF now calculate that in 2007 output gaps were large and positive. The latest OECD Economic Outlook gives 3.3% for the OECD area as a whole, 3.5% for the Euro area, 2.9% for the US and 4.4% for the UK. That is not what these organisations were saying at the time. In the June 2008 Economic Outlook, the equivalent numbers were 0.4%, 0.0%, 0.4% and 0.2%. At the time it looked like output in 2007 was close to the natural rate in many countries, including the UK. [1]

This change of view on output gaps, where 2007 goes from balance to a significant boom, is largely inevitable given the way the OECD and IMF calculate these numbers. Since the recession productivity in many countries has been much lower than we might have expected (in the UK it’s the ‘productivity puzzle’), which seems to indicate a fall in how much technical progress has been embodied in production. Traditionally we have thought of technical progress changing gradually, and as being largely unrelated to the economic cycle. If productivity is low today and technical progress only changes gradually, then it follows that some of this slackening in the pace of technical progress must have started before the recession. So in 2007 the economy was not capable of producing as much as we thought at the time.

What hard evidence do we have for all this? The living beyond our means case really comes down to the idea that both the housing bubble and the build up of personal debt must imply there was a boom. Yet this is really one piece of evidence rather than two. As Ben Broadbent shows, the build-up of debt was matched by an increase in assets: the value of houses. (The same appears to be true in the US.) This increase in personal sector indebtedness might have been foolish given what happened to house prices, but the underlying problem was the housing bubble.

Was the housing bubble an indication of a ‘hidden boom’ in 2007? There is a quite plausible alternative explanation, which is that you can get housing booms when real interest rates are low. Many economists, including Ben Bernanke, pointed out before the recession the unusually low returns on long term assets like government debt, an idea that became known as the ‘savings glut’. The return on assets was being driven down because consumers in China and its neighbours were saving extraordinary amounts, leading to large current account surpluses there. When returns on safe assets like government debt are low, people look elsewhere for higher returns, and this includes the housing market. This is probably why we are seeing rapid increases in house prices today in a number of major cities (e.g. London, Paris, Germany).

Not only is there this alternative explanation for the housing bubble, but the living beyond our means case cannot satisfactorily account for why - if we had a huge boom - inflation remained so subdued. What upward movement there was could easily be explained by large increases in oil and commodity prices. It is sometimes argued that inflation targeting, or cheap goods from China, kept a lid on consumer price inflation, but there was no indication of any overheating in the labour market either.

The second refrain, much more specific to the UK, focuses on the banking sector. The argument is not that the financial sector grew too rapidly before the recession, and must inevitably shrink back to a more normal size. That is almost certainly true, but the numbers just do not seem large enough. As Martin Wolf points out, the financial sector went from 6% of GDP in 1998 to 9% in 2008. Even if it returns to 6%, for the economy as a whole much of that should be recoverable, because most of those who have lost their jobs in the financial sector are highly skilled and so can be redeployed in other high productivity activities.

The argument is instead that, for the supply side of the economy to grow, more productive firms need to replace inefficient competitors, and new innovative start-ups should challenge existing firms. Both processes almost certainly require borrowing, and in the UK in particular that borrowing usually comes from a few large banks. If these banks stop lending, productivity growth will fall away. This argument is plausible, and can help explain two puzzles about the current recession. The first is why, when UK firms are asked how much spare capacity they have, they respond that they have very little. This is not consistent with the recession being only about lack of demand. The second is that inflation has not been falling more rapidly. If firms cannot get the finance to grow, there is little point in trying to expand your market by cutting prices.

What is frustrating about this idea is that there is little hard evidence either way. Bank lending to firms has certainly fallen, but how much of this is down to banks, and how much is simply that firms think it is too risky to borrow? (This study suggests at least some of the former.) There is a great deal of anecdotal evidence that some banks have in the last few years might have been hindering rather than helping small businesses, but translating this into actual numbers for productivity lost is almost impossible. The most compelling argument that something like this has been going on is that other explanations for the UK’s productivity puzzle are either implausible or inadequate in terms of scale.

Perhaps the key question, though, is how permanent this all is? If bank lending starts to recover, can we get back the productivity we have lost? We can look at past financial crises in other countries, as Nick Oulton has done. (His paper also provides useful detail on why other explanations for the productivity puzzle do not seem to work. The section on fiscal policy, however, departs from his usual high standards, as this article in Pieria suggests.) His analysis indicates some permanent hit to GDP from a financial crisis, but the larger numbers come from Latin America. The example of Sweden in the early 1990s is much more optimistic. A priori we might expect a good deal of the innovation to have been ‘put on hold’ because of lack of finance, and this could be activated once banks’ balance sheets are repaired. But perhaps some opportunities may have been lost forever.

Given these uncertainties, two implications for policy seem clear. First, we should stimulate demand until there are clear signs of overheating in both the goods and labour markets. We should only do otherwise if the pessimistic case is compelling, and it is not.

Second, to the extent that we do not recover the ground that we lost in the recession, the costs of the financial crisis are even larger than we thought. This suggests we must do something to make the economy less dependent on the behaviour of a small number of large UK banks. What is interesting about at least some of those who sing the pessimists’ refrain is that they seem to treat this implied loss of UK capacity like an act of God: not only is it something we can do nothing to reverse, but there is little point in investigating it further. That is a strange attitude to take, particularly given that there has been no equivalent productivity puzzle in the country where the banking crisis really started. (This may be another reason to praise small US banks: see Felix Salmon here.) Some who are pessimistic preach the usual neoliberal message for enhancing growth, including lower taxes on high incomes, but seem strangely uninterested in what has caused this alleged huge reduction in supply. Perhaps they fear the answers to the UK’s productivity puzzle will not be to their liking.

[1] For the CBO’s assessment of US potential, see Menzie Chinn.           

Unemployment, the output gap and wage flexibility

This post is about the impact of nominal and real wage flexibility on unemployment and the output gap. It starts in an academic, abstract sort of way, but the policy implications do follow. I try and make the analysis as accessible as I can to non-economists.

Start with an economy with a zero output gap (defined below) and no involuntary unemployment. Everything in the economy is just fine, which is a non-technical way of saying it is efficient. Then a ‘crisis’ happens that leads consumers to consume less and save more, so aggregate demand falls. Normally in these situations the central bank cuts nominal and real interest rates sufficiently to restore aggregate demand. Once this has happened, call everything in this economy ‘natural’, so the real interest rate that restores demand is the natural rate of interest. The natural level of output may not be the same as the pre-crisis level, because for example the new natural rate of interest can have knock on effects on how much people want to work. [1] However the natural level is the level of output that policymakers should aim for. [2]

In the Great Recession this mechanism did not work because nominal interest rates hit zero, and maybe also because monetary policy put a cap on inflation expectations. As a result, actual real interest rates are above the natural level. In addition, fiscal policy is in the hands of people who know nothing about macroeconomics, so there is no help from there. However monetary policymakers still think they could do something ‘unconventional’, so they want to know what to aim for. The answer is that, as long as what they do does not seriously distort the economy, they should try to get to the natural level of output, because that produces an efficient economy.

The difference between the actual level of output and the hypothetical natural level is called the output gap. The traditional way of defining the output gap was the difference between actual output and ‘productive potential’, which was the amount that could be produced if all factors of production were fully utilised. That is still how the gap is often measured in practice, although the measurement problems can still be huge, as Paul Krugman notes here. The problem at a conceptual level is that this approach downplays considerations of optimality, so nowadays theoretical macroeconomics uses the natural level of output to define the output gap. This has the advantage that we know what policy should be aiming to do: achieving the natural level of output.

Now imagine three almost identical economies where an output gap exists because nominal interest rates have hit zero. The level of real interest rates that would eliminate the output gap is the same in all three economies (i.e. they have the same natural levels of output). In the first economy, workers resist nominal wage cuts, so this puts a floor on how much unemployment reduces real wages. (Equally firms may be reluctant to impose wage cuts, as this research suggests - HT Kevin O’Rourke.) If nominal wages stop falling, at some point firms will stop cutting prices to protect their profits. We settle down to a new lower level of demand deficient output, high unemployment, but stable wages and prices. There is plenty for unconventional monetary policy to do, even though inflation is not falling.

In the two other economies nominal wages carry on falling. In the second economy prices get cut pari passu, so real wages remain unchanged, while in the third they do not, so real wages fall. So in the second economy inflation is lower than in the first, but real wages are the same. Does this lower rate of inflation increase or decrease the output gap? That depends only on whether actual output falls or increases because of lower inflation: the natural level of output involves a hypothetical economy which is unaffected by whether nominal wages fall or not in the actual economy [3]. Actual output may fall if negative inflation makes debtors spend a lot less but creditors not much more - this and other mechanisms are discussed in Mark Thoma’s post here. However, if monetary policymakers have been inhibited from doing much because inflation was not falling (which would be one interpretation of UK policy, for example), then as David Beckworth says, lower inflation may raise actual output by encouraging expansionary unconventional monetary policy.

How about the third economy, where real wages have fallen? Suppose firms respond to lower real wages by substituting labour for capital, and this process continues until all those who want to work can find a job. So in the third economy involuntary unemployment goes away. But is the output gap any lower? Once again, the natural level of output has not changed. (It was set in our hypothetical economy where real interest rates fell to their natural level.) So the key question becomes whether lower real wages and lower unemployment reduces or increases aggregate demand, and therefore actual output. It could go either way. So it is perfectly possible that both actual output and therefore the output gap is exactly the same in all three economies, even though unemployment has returned to its natural rate in one, and the other two have very different inflation rates. 

This comparison suggests that those who say unemployment in the first two economies is caused by wage inflexibility kind of miss the point. The basic problem is lack of aggregate demand. You could argue (I would) that the third economy is better off than the other two, because the pain of deficient demand is evenly spread (everyone has lower real wages), rather than being concentrated among the unemployed. But the first best solution is to raise aggregate demand, because that gets rid of the pain.

I started writing this post because of a recent study by Pessoa and van Reenan, who argue that the mysterious decline in UK labour productivity that I have talked about before can in large part be explained by unusually slow growth in UK real wages. The mechanism they have in mind is entirely traditional: if real wages are low firms substitute labour for capital. This in turn may explain (see Neil Irwin here for example) why UK unemployment originally rose by less than in the US (see first chart), even though the UK’s output performance was worse. On this issue looking at consumer price based measures of real wages will be misleading, so below is a very simple measure of real product wage growth in the two countries: compensation per employee less the GDP deflator. Real wage growth in the UK has noticeably fallen since the recession, whereas the fall has at least been less abrupt in the US (2013 is a forecast).

Unemployment in the US and UK: Source ONS and BLS

Growth in compensation per employee less GDP deflator: OECD Economic Outlook

In terms of just the UK economy, whether Pessoa and van Reenan are right is debatable. When I discussed this in an earlier post I referenced a Bank of England paper by MPC member Ben Broadbent, which argued that for the factor substitution story to explain most of what we have seen in the UK, investment should have completely collapsed, which it has not. This difference in view reflects a number of nitty gritty issues, like how you measure the capital stock, and whether the substitution elasticity is one (as implied by the Cobb Douglas production function), or nearer one half.

However most seem to agree that some of this factor substitution is going on in the UK. So my hypothetical discussion above suggests that, by spreading the pain of deficient aggregate demand further, this ‘real wage flexibility’ in the UK has been a good thing, but it does not mean the aggregate demand problem has decreased. If anything, it suggests that looking at unemployment underestimates the size of the output gap. Monetary policy makers please note.

[1] New Keynesian economists sometimes call the natural economy the outcome when all prices are completely flexible. That is OK, as long as we note that flexible prices here has to include the possibility that nominal interest rate can go negative, which in the real world it cannot.

[2] Opinions may differ on whether the crisis itself is a necessary correction for past errors, or whether it is itself a distortion. For example, was risk undervalued before the crisis, or is it overvalued now. In other words, was the pre-crisis economy efficient, or would there be a distortion in the post-crisis economy even without an aggregate demand problem? These are important complications compared to the story I tell here, but they will have to wait for another post.

[3] The idea is that the economies are identical except for the extent of nominal inertia in goods and labour markets. In economy 1 wages are sticky, in economy 3 prices are sticky but wages are flexible, and in economy 2 the degree of wage and price stickiness is such that real wages do not change. 

What Recession?

Tony Yates thinks there should be no more [sic] fiscal stimulus in the UK, because inflation is above target. As inflation is above target, there is no need to stimulate demand. Tony accepts that in principle at the ZLB fiscal stimulus can be a useful expansionary instrument, but in the UK at the moment it is not required.

So here is a table of CPI inflation in a few countries.

CPI Inflation rates (source: OECD Economic Outlook)

	2007	2008	2009	2010	2011	2012	2013	2014
United Kingdom	2.3	3.6	2.2	3.3	4.5	2.8	2.8	2.4
United States	2.9	3.8	-0.3	1.6	3.1	2.1	1.6	1.9
Euro area	2.1	3.3	0.3	1.6	2.7	2.5	1.5	1.2

The inflation target in the UK is 2%. So not only is there no case for any stimulus going forward, it also looks like the UK managed to completely avoid any recession in 2008/9! The US also had a small boom in 2011, and who knows why people in the Eurozone feel so depressed?

OK, this is a cheap point, but a valid one nevertheless: CPI inflation is a pretty hopeless indicator of the output gap when inflation is low. Other inflation measures do a bit better: here is the GDP deflator at basic prices.

UK Inflation: source ONS

Some of the low growth in the GDP deflator is because of low inflation in the government consumption deflator, and we know this is difficult to measure. However I’m not trying to argue that one index is better than another. Instead I just want to make the point that at low levels of inflation, inflation itself becomes a very unreliable measure of the output gap. This is true not just in the UK, as the IMF recently pointed out. 

One reason why UK inflation has not fallen further is UK labour productivity, which I have discussed before. Now if the decline in UK productivity growth was an irreversible supply side phenomenon then you could indeed argue that the current UK output gap was small (but not zero - see below), but is this remotely plausible?

Here is a chart of (logged) UK GDP since 1950. [1] I’ve added a trend line not because I believe productivity growth is always constant, but just so the following point becomes clearer. GDP growth does sometimes fall sharply: in 1980, and in 1990. But both these occasions were demand induced recessions. To argue that 2008/9 is different means that something quite extraordinary and unprecedented has happened. Now maybe that is possible, but given the costs of being wrong about this, we have to be pretty certain of your story to base policy on it. 

UK GDP, logged. Source - see [1]

So let us look at something we can measure with reasonable accuracy: unemployment.

UK Unemployment Rate: ONS

The increase in unemployment since 2008/9 is modest given the output fall - productivity again - but it is not small. I have heard no one argue that this increase in unemployment represents an increase in the NAIRU or natural rate. To the extent that low real wage growth has encouraged substitution from capital to labour, unemployment underestimates the extent of the output gap. (If unemployment continues to fall at the same rate it has over the last year - a rate the Employment Minister describes as encouraging - we should see a return to pre-recession levels sometime after 2025.)

So it seems to me that we are sitting in a freezing house, but because the thermostat says it is still warm, its occupants are trying to convince themselves that they are not really feeling cold, and the last thing they want to do is turn up the heat. (I admit not the best of analogies for the UK right now.) Just because we build models in which inflation always responds in a predictable and linear way to the output gap, does not mean that the real world behaves in the same way.

[1] I’ve spliced the recent ONS data revision from 1998 on to a time series from Lawrence H. Officer and Samuel H. Williamson, 'What Was the U.K. GDP Then?' MeasuringWorth, 2012.

Why Inflation is not falling

There has been considerable interest in the recent IMF study that found that the responsiveness of inflation to the output gap (or equivalent measure) falls at low levels of inflation. But if the econometrics is right (and Nick Rowe has some cautionary tales here), what is the explanation for this? I start with two standard stories, but then suggest other possibilities that are specific to current financial conditions.

One standard explanation which the paper itself gives is based on the menu cost model of price inertia. The idea is that firms do not change their prices that often because there are costs to making any change (which economists call menu costs, perhaps betraying how often they spend in restaurants rather than buying food in supermarkets), and that often this cost might be higher than any benefit to profits in making a change. If you derive the aggregate relationship between inflation and the output gap from a model of this kind, the coefficient on the output gap will depend on how frequently prices are changed. So if price changes become more infrequent at low levels of inflation, the sensitivity of inflation to the output gap will fall.

Another quite plausible story which has solid empirical backing is that workers particularly resist nominal wage cuts. That actually implies an asymmetry in response rather than a general reduction in sensitivity (if the output gap was positive workers would happily see wages rise), but it will affect the average response in an econometric study that does not allow for asymmetry, and in current circumstances it is an entirely appropriate story.

You might think that enough, but I have a UK-centric reason for wanting more. In the UK, the ‘wages’ Phillips curve does not seem to be showing any reduction in sensitivity - indeed perhaps the opposite (although any additional sensitivity seems to predate the recession). That does not mean workers are not resisting nominal wage cuts, but the overall impact of this has either been small, or has been offset by something else.

The story I want to tell involves firms’ pricing behaviour, and the role of more risk averse banks. Suppose a firm sees demand for its output fall. Its profits are lower, but it calculates that it can reduce that decline in profits by cutting its price, if that price cut increases demand. There are two risks involved in doing this. First, the price cut might raise demand by much less than expected, with the consequence that profits fall further still. Once the firm realises this it can always put prices back up again, but in the short run profits will decline. Second, it may take time for the price cut to feed through into higher demand: those buying competing products may not immediately realise that they should switch. So although profits might rise eventually, they could fall in the short run.

So in both cases, there is a risk that profits in the short run might suffer as a result of the price cut. In normal times firms would be prepared to take those risks, either because the risks are symmetric (maybe demand will increase by more than expected), or because they represent an investment with a positive eventual payoff (as customers switch products). Critically, even if the short run might actually bring losses rather than profits, the firm’s bank will cover the losses because it is taking a long term view.

However, since the financial crisis, the firm may have noticed that the behaviour of its bank has changed. It refused the business down the road any credit, even though by all accounts its difficulties were clearly temporary. Although the firm would like to cut prices in the expectation that this will eventually raise profits, if the price cutting idea does not work out and the bank plays tough that could mean bankruptcy.

The idea is that the aftermath of the financial crisis, by raising the risk of bankruptcy associated with short term losses, has lead to greater price rigidity. In addition, there are two related effects that could actually lead to higher inflation in the short run. First, the firm does not like the fact that it can no longer depend on the bank to cover any short term losses. Who knows what might happen. So although a price increase might reduce profits if sustained (as customers gradually switch), in the short run profits will rise, and that allows the firm to pay off those debts which would otherwise keep its owners awake at night. This is the firm as a precautionary saver. Second, firms might be keeping prices low not because of existing competition, but because of the threat that a new start-up might emerge and steal some of its business. The one silver lining of the financial crisis for existing firms is that new start-ups are much less likely to get any money from the bank, so this diminished threat of new entry allows the firm to safely increase its profit margins.

I have absolutely no evidence that any of this has been happening, or indeed whether these ideas stand up to serious analysis. I don’t know of any papers that have explored the impact of financial frictions of this kind on prices, but that may well be my fault, so please point me to any you know. If there is anything in these ideas, then they caution against interpreting any current rigidity in inflation as evidence against demand deficiency.