Forecast errors compared

And a coda defends experts against Aditya Chakrabortty

A recent conversation got me thinking about different types of macroeconomic forecast error, and what implications they might have for macroeconomics. I’ll take three, from a UK perspective although the implications go well beyond. The errors are the financial crisis, the lack of a downturn immediately after Brexit, and flat UK productivity.

The immediate cause of the Global Financial Crisis (GFC) was the US housing market crash, but that alone should have caused some kind of downturn in the US, with limited implications for the rest of the world. What caused the GFC was the lack of resilience of banks around the world to a shock of this kind.

Were there any indications of this lack of resilience? Here is an OECD series for banking sector leverage in the UK: the ratio of bank assets to capital. The higher the number, the more fragile banks are becoming.

UK Banking sector leverage: Source OECD

The first and perhaps most important problem with forecasting the financial crisis was that macro forecasters were not looking at data like this. For most it was not on their radar, because banks, let alone bank leverage, played no role in their models. It was a sin of omission, a big gap in our macro understanding. (Whether, if forecasters had been having to forecast this data, they would have predicted a crisis is improbable, but some would have at least noted it as an issue.)

Moving on to the second mistake, it is often said (correctly) that forecasters are very bad at predicting turning points or dramatic changes. But many did predict such a change immediately following the Brexit vote: a sharp and immediate slowdown in demand caused by the uncertainty of Brexit. It didn’t happen. The main reason was consumption, which held up by more than people were expecting, given the fall in real incomes that was likely to come from the Brexit depreciation. There are two and a half obvious explanations for this. First, because of Leave propaganda half the population thought Brexit would make them at least no worse off. Second, those who did anticipate the rise in import prices may have taken the opportunity to buy consumer durables made overseas to beat the prospective price increase. The half is that the Bank cut interest rates a bit.

None of these effects are very new. They may not have been incorporated into the forecasters’ models, but they could in principle have been incorporated using the forecaster’s judgement, although getting the quantification right would have been very difficult. In the end we got the slowdown, but delayed until the first half of this year, as Leavers began to face reality and the higher import prices came through, so it was an error of timing more than anything else (although it was apparently enough to make MP Liz Truss change her mind and support Brexit!). You could describe it as an unchallenging error, because it could easily be explained using existing ideas. It is the kind of error that forecasters make all the time, and which makes forecasting so inaccurate.

The third error was UK productivity, which I talked about at length here. Until the GFC, macro forecasters in the UK had not had to think about technical progress and how it became embodied in improvements in labour productivity, because the trend seemed remarkably stable. So when UK productivity growth appeared to come to a halt after the GFC, forecasters were largely in the dark. What many like the OBR did, which is to assume that previous trend growth would quickly resume, was not the extreme that some people suggest. It was instead a compromise between continuing no growth and reverting to the previous trend line, the second being what had happened in previous recessions.

My point of writing about this again is that I think this third error is much more like the GFC mistake than the post-Brexit vote mistake. In both cases something important that forecasters were used to taking for granted started behaving in a way that had not happened since WWII. Standard models were used to treating technical progress as an unpredictable random process. Now it is just possible that this is still the case, and the absence of technical progress in the UK and to a lesser extent elsewhere is just one of those things that will never be explained. But for the UK at least the coincidence with the GFC, austerity and now Brexit seems too great. As as I showed in the earlier post growth has not been exactly zero but has oscillated in a way that could be related to macro events.

If there is some connection, both in the UK and elsewhere, between the decline in economic productivity growth and macroeconomic developments, then this suggests an important missing element in macromodels. And like the financial sector, there is an existing body of research that economists can draw on, which is endogenous growth theory. There are examples of that happening already.

But I want to end with a plea. After the financial crisis too many people who should have know better said that failing to predict the financial crisis meant that all existing mainstream macroeconomics was flawed. It was rubbish, but such attitudes did not help when some of us were arguing against austerity on the basis of standard macroeconomic ideas and evidence. Now with UK productivity, we have Aditya Chakrabortty saying that experts at the OBR “are guilty of a similar un-realism and they have proven just as impervious to criticism” as people like Boris Johnson or Liam Fox. Not content with this nonsense, he says “This age of impossibilism is partly their creation”.

This is just wrong. Look at the elements of neoliberal overreach. Economists didn’t start calling for tight immigration controls and using immigrants as a scapegoat for almost everything. Most academic economists did not call for austerity. Almost all economists did not want to get rid of our trade agreements with the EU. Even if economists had warned about the financial crisis they would have been ignored because of the political power of finance. If all economists had thought productivity would continue flat we would have just had more austerity. [1] And in making this basic mistake, it is ironically Aditya Chakrabortty who has joined Michael Gove and other Brexiteers in having had enough of experts.

[1] Less expected productivity growth means lower future output which means lower future tax receipts which means, given the government’s austerity policy, more cuts in public spending.

Economists as medics

I got some stick on twitter the other day for my (longstanding) view that economics is in many respects like medicine. It is of course not exactly like medicine: as the man said, economics is an inexact and separate science. But think about what most doctors spend their time doing. They are in the business of problem solving in a highly uncertain environment in which they only have a limited number of clues to go on. They have solutions to a subset of problems that work with varying degrees of reliability.

If you read Dani Rodrik’s book Economics Rules (which if you have not you should, and can the person who borrowed my copy return it please!), you will see that economists have a large number of distinct models, and the problem that many economists spend their time solving is which model is most applicable to the problem they have been asked to solve. Where doctors have biology as the underlying science behind what they do, they also rely on historical correlations to see if the science is appropriate. Think about solving the problem of why there had been an increase in lung cancer in the middle of the last century.

The science for economists is microeconomic theory, now enriched by behavioural economics. Most of the models economists use are derived from this theory. But as Rodrik emphasises, the trick is to know which model is applicable to the problem you have been asked to solve. To help solve that problem, economists, like doctors, want data. Many have observed how journal articles are now more likely to be about investigating data than establishing theoretical results. Economists have recently started adopting the terminology of medicine in economic studies, talking about treatment effects for example. We both do controlled trials (for economists, mainly in development economics).

Sometimes the paths of the two disciplines cross (as they do all the time, of course, in health economics). One of the big empirical discoveries of recent years has been by Case and Deaton, looking at mortality rates of the US white population. Here is a key figure from their 2015 study.

Mortality has been falling steadily almost everywhere, except since just before 2000 among US whites. Focusing just on the US, the problem seems to be mainly for non-college educated whites (this graphic comes from here).

As with anything to do with race and class in the US, this work has been controversial, but some excellent analysis from Noah Smith shows that the problem suggested by the data is real enough.

Case and Deaton have a new study which tries to understand why this is happening. They describe it as evidence of ‘deaths of despair’. In each age cohort among this group, deaths from suicide, drug overdose or alcohol have been steadily rising. Some useful data is shown here. The interpretation the authors give for the despair is the decline in economic circumstances and status of the white working class in the US.

One of the factors that they describe as an ‘accelerant’ in this development has been the overprescription of opioids drugs that provide short term pain relief, but which have negative consequences in the longer term. US policy over the last 20 years has led to what some describe as the

“worst drug epidemic in U.S. history. Enough opioids are prescribed in the United States each year to keep every man, woman and child on them around the clock for one month.”

They go on

“It is hard to believe that medicine, which prides itself on empiricism, could have taken such a wrong turn.”

Of course individual doctors make mistakes all the time, but the profession as a whole can make major mistakes. It is of course subject to pressures from individuals and large organisations (drug companies). In this, again, it is like economics.

Consider this chart, taken from Alan M. Taylor, ‘The Great Leveraging’, NBER WP 18290.

The blue line shows the percentage of high income countries experiencing a financial crisis each year. Crises were endemic until after WWII, when it appeared for two decades or more that they were a thing of the past. In the 1980s they returned, but without any major impact on high income countries. Then there was Japan’s lost decade, and plenty of papers were written about how that was a particularly Japanese problem. The 2000s seemed quiet, and some called it the Great Moderation, until the global financial crisis arrived.

Looking at this chart, it is hard to believe that economics, that prides itself on its empiricism, could have made the mistake of believing that now things were different. But economics, like medicine, can make big as well as small mistakes. The point I want to make here is the different nature of the response to these mistakes from outside these disciplines. No one says that medicine has failed us, and we need to find fresh voices. No one will say that ‘mainstream medicine’ is in crisis, and we need to look at alternatives.

They do not say that because it would be stupid to do so. With the opioid epidemic something has gone very wrong and it needs to be corrected, and the same is true for economics and the financial crisis. So why the overreaction when it comes to academic economics? One reason is that doctors are not generally asked how long people will live, and even when they do their forecasts are not published almost every day in the press. Most economists are as honest as doctors would be about that kind of unconditional forecasting, but it suits the media to appear shocked and surprised when things go wrong. Another reason is that ordinary people can see doctors doing good things all the time to themselves, their friends and families, but the work of economists is felt less directly. It also seems intuitive that medics are in some sense better than economists, although how you could measure that I do not know. Both factors may explain why medicine is internally policed to a large degree (doctors can be stopped from practicing), whereas economics is not.

Another big difference involves politics. Economists bring unwelcome news to both left and right, so it suits both sides to occasionally bash the discipline that brings the message. We have seen a great deal of that from the right over Brexit. For the left more than the right there are also non-mainstream economists who have an interest in arguing that the mainstream has been corrupted by ideology. Quite why so many on the left choose to attack mainstream economics rather than use the mainstream to attack the right I do not know. All I do know is that they have been doing it for 40+ years, as I remember being told by many economists that the mainstream was fatally flawed back in Cambridge in the early 1970s, which was before Thatcher and Reagan.

But these differences should not obscure the similarities between economics and medicine. We both deal with people, and their mind and body can be pretty complicated whether as individuals, or as a society. In some areas we have developed quite detailed degrees of quantitative understanding that allow us to make successful interventions (more so than in other social sciences I suspect). In other areas we do things that work most of the time but sometimes fail, but there are many important areas where if we are honest we do not have any real idea of what is going on. So we make mistakes, which can sometimes be extremely costly for huge numbers of people, but we also learn from these mistakes.

The Kerslake Review of the Treasury

This review, published today, was commissioned by John McDonnell but is entirely independent. Although it is ultimately Lord Kerslake’s review, it is the product of a small panel of which I was a member, and also reflects submitted evidence and meetings of invited experts. I can say that in my area, macroeconomic policy, this external evidence was very influential and let me thank again all those involved. This post just focuses on these macroeconomic aspects of this review of the Treasury. [1]

The obvious place to start is to think how the role of the Treasury has changed in the last two decades. In 1997 setting monetary policy was delegated to the Bank of England. In 2010 the forecasting aspects of fiscal policy were delegated to the OBR. To a government obsessed by cutting the size of the state that might suggest that the Treasury did not need to have a large macroeconomic capacity, But if you think about the major macroeconomic disasters if the last decade, that view is completely misguided.

One way of thinking about these disasters is that they reflect a failure to consider potential risks to the economy, and what might be done to both mitigate those risks and respond to them if they occurred. No one was ever going to predict the exact time and date of the financial crisis, but someone in government should have been thinking about what risks a rapidly expanding banking sector might pose. There were not many who warned about the risks, but enough to warrant a risk analysis. As I have said before, I doubt that this could have avoided a crisis - the banking lobby is too strong - but at least the government would have given some thought about what to do if it happened before it happened.

When it came to austerity, everything would have been relatively unproblematic if the economy had grown at the pace at first expected in 2010, because monetary policy would still have had control. (Interest rates would have been above their lower bound.) But someone should have been focusing on what happens if things turned out to be less rosy, and making sure ministers had to address these risks. At the very least that analysis would have pinpointed the need to change fiscal policy the moment that more pessimistic outcome came to pass, but perhaps also thinking about this risk might have injected a note of caution into policy before this happened. In a secret Treasury that might not have stopped a determined politician, but if this risk analysis had been made public?

Who in government should have been doing this risk analysis? The obvious institution is not the central bank, which can be far too tentative in the area of fiscal policy and too biased on financial policy, but the Treasury. The Treasury, to use a phrase suggested at one of our evidence gathering meetings, should be “the country’s risk manager of last resort”. The Treasury is uniquely capable of getting information from all the parts of government, including the Bank, and putting it together within a consistent macroeconomic framework.

But this isn’t the only reason why the Treasury still needs a strong macroeconomic capacity. It sets the rules by which fiscal and monetary policy operate, and the danger of not having this capacity is that the rules get determined by political whim, or don’t change through inertia. And it also needs the capability to undertake large pieces of complex analysis very quickly, as we have again seen over the last two decades.

What do I mean by capacity? Above all people: people who have the ability to do and understand state of the art macro analysis. If you compare the number of macroeconomists at the Treasury and the Bank there is a huge imbalance which is not conducive to good policy making. It is absurd to think that you need suites of models to set interest rates, but virtually nothing to set monetary and fiscal policy rules and analyse the impact of potential risks to the economy.

None of this is guaranteed to stop the Treasury become obsessed with the deficit and ignoring macro analysis, but the stronger the macro team is in the Treasury the less likely this is to happen. One other way that is often suggested of combating this danger, and which we considered, involves splitting off from the Treasury key aspects including macro policy into a new Economics ministry. My own view, which is similar to that expressed in the report, is that such a split just runs the danger of institutionalising the dominant role of balancing the budget in policy making.

There is one final benefit of enhancing the macro capacity of the Treasury, and that would be to provide the potential to increase openness. I take it as given that greater openness would be a good thing, and also being an essential way of utilising existing expertise around the country. It is far from clear why risk anaysis has to be secret. To take just two examples, the Bank makes a concerted attempt to find out what is being done in UK universities that might be useful to it, and it publishes a regular blog where their economists can flag interesting data and analysis. It would be good if the Treasury had the capacity to do something similar.

[1] There is a great deal more in the report, both about macro policy and issues around devolution, working with other departments, the overall goals of policy and much more. I also feel I need to note one area where I disagree with how Bob talked about the report yesterday (on Peston’s show and to the Guardian). While I’m sure it is true that the Treasury has lost trust as a result of its incorrect pre-referendum short term forecast, by highlighting this in the context of this report you inevitably give the impression that it did something unprofessional. But both assessments were signed off by Charlie Bean. and the Treasury were hardly alone in expecting negative short term impacts from Brexit. Worse still, it risks suggesting that their long term analysis is suspect.

Attacking economics is a diversionary tactic

Forgive the numbered note form. For some reason it seems appropriate to me in this case

1. The financial crisis in the UK was the result of losses by banks on overseas assets, originating from the collapse in the US subprime market. It was not a result of excessive borrowing by UK consumers, firms or our government. As the Bank’s Ben Broadbent points out, “Thanks to the international exposure of its banks the UK has been, in some sense, a “net importer” of the financial crisis.” This overseas lending caused a crisis because banks were far too highly levered, and so could not absorb these losses and had to be bailed out by the government.
   
   
2. This is why UK macroeconomists failed to pick up the impending crisis. They did routinely monitor personal, corporate and government borrowing, but not the amount of bank leverage. Macroeconomists generally acknowledge that they were at fault in ignoring the crucial role that financial sector leverage can play in influencing the macroeconomy. There has been a huge increase in the amount of research on these finance-macro linkages since the crisis.
   
   
3. But supposing economists had ensured that they knew about the increase in bank leverage and had collectively warned of the dangers of excessive risk taking that this represented. Would it have made any difference? There are good reasons for thinking it would not.
   
   
4. The main evidence for this is what has happened after the crisis. Admati and Hellweg have written persuasively that we need a huge increase in bank capital requirements to bring the ‘too big to fail’ problem to an end and avoid a future banking crisis, and the work of David Miles in the UK has a similar message. I have not come across an academic economist who seriously dissents from this analysis, but it has no impact on policy at all. The power of the banking lobby is just too strong.
   
   
5. So the response of economists to the financial crisis has been as it should be. The error in neglecting bank leverage is being addressed. Economists have come up with clear proposals about how to avoid the crisis happening again. And these proposals have been pretty well ignored.
   
   
6. In terms of conventional monetary and fiscal policy, academic economists got the response to the crisis right, and policymakers got it very wrong. Central banks, full of economists, relaxed monetary policy to its full extent. They created additional money, rightly ignoring those who said it would bring rapid inflation. Many economists, almost certainly a majority, supported fiscal stimulus for as long as interest rates were stuck at their lower bound, were ignored by policymakers in 2010, and have again been proved right.
   
   
7. So given all this, why do some continue to attack economists? On the left there are heterodox economists who want nothing less than revolution, the overthrow of mainstream economics. It is the same revolution that their counterparts were saying was about to happen in the early 1970s when I learnt my first economics. They want people to believe that the bowdlerised version of economics used by neoliberals to support their ideology is in fact mainstream economics.
   
   
8. The right on the other hand is uncomfortable when evidence based economics conflicts with their politics. Their response is to attack economists. This is not a new phenomenon, as I showed in connection with the famous letter from 364 economists. With austerity they cherry picked the minority of economists who supported it, and then implemented a policy that even some of them would have disagreed with. (Rogoff did not support the cuts in public investment in 2010/11 which did most of the damage to the UK economy.) The media did the rest of the job for them by hardly ever talking about the majority of economists who did not support austerity.
   
   
9. The economic costs of Brexit is just the latest example. Critics have focused on the most uncertain and least important predictions about Brexit, made only by a few, to attack all Brexit analysis. The fact that this prediction involved an unconditional macro forecast, while the assessment made by a number of groups about the long term cost involves a conditional projection based largely on trade equations, seems to have completely escaped the critics. More important, the fact that the predicted depreciation in sterling happened, and is in the process of already causing a large drop in living standards, is completely ignored by these critics.
   
   
10. Attacking economists over Brexit is designed to discredit those who point out awkward and uncomfortable truths. Continuing to attack economists over not predicting the financial crisis, but failing to ignore their successes, has the effect of distracting people from the group who actually caused this crisis, and the fact that very little has been done to prevent a similar crisis happening in the future.
    

Ricardian Equivalence, benchmark models, and academics response to the financial crisis

Mainly for economists

In his further thoughts on DSGE models (or perhaps his response to those who took up his first thoughts), Olivier Blanchard says the following:

“For conditional forecasting, i.e. to look for example at the effects of changes in policy, more structural models are needed, but they must fit the data closely and do not need to be religious about micro foundations.”

He suggests that there is wide agreement about the above. I certainly agree, but I’m not sure most academic macroeconomists do. I think they might say that policy analysis done by academics should involve microfounded models. Microfounded models are, by definition, religious about microfoundations and do not fit the data closely. Academics are taught in grad school that all other models are flawed because of the Lucas critique, an argument which assumes that your microfounded model is correctly specified.

It is not only academics who think policy has to be done using microfounded models. The core model used by the Bank of England is a microfounded DSGE model. So even in this policy making institution, their core model does not conform to Blanchard’s prescription. (Yes, I know they have lots of other models, but still. The Fed is closer to Blanchard than the Bank.)

Let me be more specific. The core macromodel that many academics would write down involves two key behavioural relationships: a Phillips curve and an IS curve. The IS curve is purely forward looking: consumption depends on expected future consumption. It is derived from an infinitely lived representative consumer, which means Ricardian Equivalence holds in this model. As a result, in this benchmark model Ricardian Equivalence also holds. [1]

Ricardian Equivalence means that a bond financed tax cut (which will be followed by tax increases) has no impact on consumption or output. One stylised empirical fact that has been confirmed by study after study is that consumers do spend quite a large proportion of any tax cut. That they should do so is not some deep mystery, but may be traced back to the assumption that the intertemporal consumer is never credit constrained. In that particular sense academics’ core model does not fit Blanchard’s prescription that it should ‘“fit the data closely”.

Does this core model influence the way some academics think about policy? I have written how mainstream macroeconomics neglected before the financial crisis the importance that shifting credit conditions had on consumption, and speculated that this neglect owed something to the insistence on microfoundations. That links the methodology macroeconomists use, or more accurately their belief that other methodologies are unworthy, to policy failures (or at least inadequacy) associated with that crisis and its aftermath.

I wonder if the benchmark model also contributed to a resistance among many (not a majority, but a significant minority) to using fiscal stimulus when interest rates hit their lower bound. In the benchmark model increases in public spending still raise output, but some economists do worry about wasteful expenditures. For these economists tax cuts, particularly if aimed at those who are non-Ricardian, should be an attractive alternative means of stimulus, but if your benchmark model says they will have no effect, I wonder whether this (consciously or unconsciously) biases you against such measures.

In my view, the benchmark models that academic macroeconomists carry round in their head should be exactly the kind Blanchard describes: aggregate equations which are consistent with the data, and which may or may not be consistent with current microfoundations. They are the ‘useful models’ that Blanchard talked about in his graduate textbook with Stan Fischer, although then they were confined to chapter 10! These core models should be under constant challenge from both partial equilibrium analysis, estimation in all its forms and analysis using microfoundations. But when push comes to shove, policy analysis should be done with models that are the best we have at meeting all those challenges, and not models with consistent microfoundations.

[1] Recognising this point, some might add some ‘rule of thumb’ consumers into the model. This is fine, as long as you do not continue to think the model is microfounded. If these rule of thumb consumers spend all their income because of credit constraints, what happens when these constraints are expected to last for more than the next period? Does the model correctly predict what would happen to consumption if the proportion of rule of thumb consumers changes? It does not.  

The total failure of the centre left

We have already begun to hear laments that Corbyn’s second victory means the end of Labour as a broad church. This is nonsense, unless that church is one where only people from the right and centre of the party are allowed to be its priests. Alison Charlton (@alicharlo) responded to my tweet to that effect by saying “It's the soft left, like me, who shouldn't be priests. We're rubbish at it.”

That I think captured my thoughts this last weekend. As Steve Richards writes “The so-called shadow cabinet rebels must be the most strategically inept political group in the history of British politics.” And although they were never the tightly knit group of coup plotters that some Corbyn supporters imagined, their collective thinking was completely flawed. It was self-indulgent folly by the minority group that I call the anti-Corbynistas to constantly spin against Corbyn from the start: as I predicted, it was totally counterproductive. But it was equally naive of centre-left MPs who nominated Owen Smith to believe that all they needed to do was adopt the leadership’s economics policies.

Forget all you read about Smith not being experienced enough, or about how he made gaffes (journalists just love gaffes), how he could have run a better campaign and so on. This is stuff and nonsense. Just as with Sanders in the US, Corbyn’s support is the result of a financial crisis the after effects of which we are still suffering from and where the perpetrators have got away largely unscathed. The crisis came as a complete surprise to the political centre, and only those on the left had warned about growing financialisation. Yet these warnings went unheeded by the Labour party, in part because the left had become marginalised. That is why politicians like Sanders and Corbyn can talk about the financial crisis with a conviction that others cannot match, and their supporters see that. The constant UK refrain about entryism is, frankly, pathetic.

In those circumstances Owen Smith had a mountain to climb. I wrote on 1st August a list of things he needed to do to win. Crucially he failed to back reducing the number of MPs required to nominate a candidate for leader, which in practice excluded any successor to Corbyn from the left being able to run. I wrote “If Smith wants Labour members to trust him, he has to show that he also trusts them in the future.” I also suggested he should now offer John McDonnell the job of shadow chancellor to show he meant to unify the party. How naive I was, some retorted: didn’t I know McDonnell was hated by much of the PLP. Of course I knew, which was partly why it was a good idea: at least I was trying to show some imagination that seemed absent from the PLP. Team Smith even seemed unable to acknowledge McDonnell’s positive achievements, like the Economic Advisory Council (EAC) and the fiscal credibility rule. No wonder he lost.

There is no getting away from the fact that the vote of no confidence is going to be fatal to Labour’s chances at the General Election. Of course Corbyn’s performance had been extremely poor, and he ran a deeply flawed Brexit campaign. But the no confidence vote was a do or die act, and the chances of it succeeding were always minimal. That is political ineptitude: sacrificing your party’s election chances for slender odds. All MPs can do now is help minimise the scale of that defeat, and if some feel that given all that they have said about the leadership that is best done from the backbenches Corbyn supporters should respect that. They should use the spare time to think about how to revitalise the centre left, but keep these and other thoughts out of the public eye. Talk of sacrificing being part of the single market so we can end freedom of movement is not a good start. As Chris Dillow argues, they are not even worthy of the label Blairite.

What Corbyn needs to do is clearly set out by Owen Jones here. To say he has a mountain to climb is an understatement. He carries the weight of the no confidence vote. Even if the PLP now unites behind him, much of the media will act as if it does not. He risks being outflanked in the traditional heartlands by UKIP: if voters think their problems really would be reduced with less immigration (and which politicians are telling them otherwise?), they will vote for the party that talks about little else. In the new heartlands of London and other cities, anti-Brexit feeling may well find LibDem clarity on the issue attractive. (Corbyn’s margin of victory in London was small.) Corbyn's ridiculing of warnings about the economic cost of Brexit (despite the advice of his EAC) does not set him up well to capitalise on any bad economic news.

In short, if he manages to defeat the Conservatives in 2020 it will be one of the most remarkable achievements in UK political history. Even to come close would be a great success. For what it is worth I hope he does, if only because it would force the centre-left to finally recognise their failure since the financial crisis.

Why the political centre needs to be radical

In a recent article on Tony Blair, George Eaton wrote:

“[Blair] said of Corbyn’s supporters: “It’s clear they can take over a political party. What’s not clear to me is whether they can take over a country.” It was Blair’s insufficient devotion to the former task that enabled the revival of the left. As Alastair Campbell recently acknowledged: “We failed to develop talent, failed to cement organisational and cultural change in the party and failed to secure our legacy.” Rather than effecting a permanent realignment, as the right of the party hoped and the left feared, New Labour failed to outlive its creators.”

I beg to differ. The rise of Jeremy Corbyn is not a result of Blair failing to “cement .. cultural change in the party”. It is a result of the financial crisis, of everything that has followed from that, and the centre’s failure to offer a radical response to that momentous event.

Echos of the financial crisis are everywhere for those that care to listen. Even in the EU referendum, which at first sight is about free trade areas and sovereignty. The main reason Brexit has such wide popular support is concern over immigration, and that in turn is driven by a belief that immigration reduces real wages and puts pressure on public services. Yet the main reason public services are under pressure is austerity, which in turn was a reaction to the financial crisis. Immigration improves the public finances. The main reason for the decline in real take home pay for the low paid is not immigration but stagnant productivity following the financial crisis (and increasingly austerity measures).

The financial crisis was a major event not just in its consequences, but because it raised crucial questions about our current economic system. For most on the political right that question was too threatening to contemplate, so they doubled down by reducing the size of the state using deficit deceit as a means. But as many people did not want less spent on the things the state does, and a smaller state did nothing to immediately inspire the private sector, that only intensified popular frustration with the economic status quo.

Rescuing the banks should have been a prelude to radical reform of the financial sector, yet the centre only seemed to be concerned with putting the pieces back together again and making minor changes that are very vulnerable to being unravelled by political pressure from the banks. In many countries the centre seems paralysed by the glare of populism, whether that populism is used by governments (austerity) or the far right.

For the UK’s centre-left this paralysis comes in a particular form called ‘electability’. Radical policies almost by definition upset the status quo, who will attempt to frame such policies as anti-business or anti-aspiration. If electability becomes synonymous with avoiding anything that might be framed in this way, that rules out radical solutions. Yet radical events or profound changes in society and the economy may well require radical solutions, and if the centre avoids them they let people like Donald Trump or Boris Johnson in.

In a recent article Dani Rodrik wrote about populist politics in response to the impact of inequality and globalisation, but it could equally apply to the financial crisis. The two are connected of course: it was the globalisation of finance rather than anything happening in the UK economy that destroyed UK banks.

“The appeal of populists is that they give voice to the anger of the excluded. They offer a grand narrative as well as concrete, if misleading and often dangerous, solutions. Mainstream politicians will not regain lost ground until they, too, offer serious solutions that provide room for hope. They should no longer hide behind technology or unstoppable globalization, and they must be willing to be bold and entertain large-scale reforms in the way the domestic and global economy are run.”

Economists are losers so ignore them on Brexit

That essentially is the argument of the Telegraph’s Allister Heath, expressed as Donald Trump might. Heath says we have a been failures for over a century, “yet they now have the chutzpah to behave as if they should be treated like philosopher kings, an all-knowing “profession” that we are all supposed to bow down to uncritically.”

Actually right now I think we would settle for being heard. Ironically the only people in the media who seem to have noticed our Times letter are those supporting Leave. This matters. Recent polling evidence suggests voters have taken on board the Bank of England’s view that we will be worse off in the short term. But when it comes to the economy in 10 to 20 years time, as many voters think we will be better off by leaving as think otherwise. That the overwhelming majority of academic economists think there are significant long term costs to leaving might therefore be useful information for voters: information many currently do not have. So much for “philosopher kings”.

Of course economists have many faults and do make mistakes. But it remains the case that economists do know more about what determines trade and foreign investment and the impact of migration than most. We certainly know more than political journalists.

Should our expertise be ignored? Let’s look at some of the evidence Heath uses to suggest we nearly always get it wrong. The first is a poll conducted by the Economist in 1999 about whether the UK should join the Euro. Here the split was basically 2 in favour for every one against. But there is a crucial difference from Brexit. In the case of the Euro every economist would acknowledge (see the Economist article) that there were good arguments for and against. In the case of Brexit the only matter to discuss is how big the costs of leaving are. Our trade can only decrease following Brexit. Foreign direct investment can only decrease. Migration, which is also a plus for the economy as a whole, is likely to decrease following Brexit.

The main argument those supporting Brexit use to suggest the economy will do better is that we can get rid of all those pesky regulations that are holding business back. Which was exactly the argument the Conservatives and those in the financial sector made when they championed reducing regulations on finance before 2008. It worked for a few years, and then we had the financial crisis that led to the biggest post-war recession. Mr. Heath has the chutzpah to lay all the blame for that on economists.

But let’s roll the Euro story on to 2003. The government had to make a decision, and this focused on the economics. It commissioned a huge amount of work looking at all the evidence, consulting widely among academics. These studies flagged up some (not all) of the vulnerabilities of the Eurozone that became evident in subsequent years. This persuaded first Gordon Brown and then Tony Blair to say no. I would count that as a definite win for economists.

Of course he mentions what he calls the ‘infamous’ letter from 364 economists in 1981 criticising the Conservative deflationary budget. We are told that the 364 got it wrong because the economy started growing shortly afterwards. This is mediamacro logic, just like when we were told austerity was a success in the UK because the economy grew in 2013. As Steve Nickell pointed out in this speech, unemployment peaked not in 1981 but 1986. The combination of monetary and fiscal contraction in 1981 was overkill, and on that fundamental point the letter was right.

But I will concede this. Mr. Heath and his colleagues on the neoliberal right are much better at PR than economists. They have managed to create the perception in the media that the letter was wrong and Mrs. Thatcher was right. Their strategy is that if the evidence is against you, distort the evidence.

This is the real beef that Mr. Heath has against economists: we mostly follow the evidence and not an ideology. Most economists were indeed wrong about the Great Depression, but that led to the creation of macroeconomics as a separate discipline under the guiding light of Keynes. This helped produce a golden age of growth after WWII, a fact that Mr. Heath ignores. It was brought to an end by stagflation, but that was not the surprise to economists that Mr. Heath imagines.

The irony is that the ideology Mr. Heath follows is itself based on economics: economics as understood by a first year student who only listened to a third of their lectures. For Heath economics is fine as long as it is explaining the virtues of the market and competition, but if economists look at market imperfections then they are “obsessed”.

When I see Heath and his compatriots extol the virtues of the regulation free world that will be possible once they are freed from the shackles of the EU, I am reminded of the Troika and Greece. The Troika has been effectively running Greece for 6 years, yet unlike Ireland or Spain the economy remains in depression with no signs of hope. But rather than question what they have done, they blame the Greeks for not pursuing the prescribed policies rigorously enough. The UK is one of the least regulated OECD economies, and has recently had 6 years of government spending cuts and corporation tax cuts, but productivity growth since the crisis has been painfully slow. Rather than question the efficacy of the medicine, the ideologues blame the EU from preventing them doing even more.

It also reminds me of the Scottish referendum, where those in favour of independence just did not want to hear the bad news about the short term fiscal outlook. Some decided that those bringing that news were part of some Westminster conspiracy, and all preferred to believe the wishful predictions of the SNP. I’ll repeat now what I said then: do you really want to be ruled by people who prefer make believe stories to evidence, and who are so desperate for votes they tell you to ignore an entire academic discipline.           

Explaining the last ten years

The Great Recession was larger than any previous post WWII recession. But that is not what it will be mainly remembered for. Unlike previous recessions, it appears to have led to, or coincided with, a permanent reduction in the productive potential [1] of the economy relative to previous trends. As unemployment today in the US and UK is not very different from pre-recession levels, then another way of saying the same thing is that growth in labour productivity and real wages over the last seven years has been much lower than pre-recession trends. (As employment has not yet recovered in Europe, I will focus on the US and UK here.)

I have posted charts showing this for the UK many times, so here is something similar for the US. It plots the log of real GDP (green) against the CBO’s (Congressional Budget Office) estimate of potential output (yellow). Unlike the UK, potential growth in the US does not appear constant from 1955, but the CBO has potential output growth between 3 to 3.5% in most years between 1970 and the early 2000s. The break created by the Great Recession is clear: potential growth fell to as low as 1% immediately after the recession, is currently running at 1.5%, and the CBO hopes it will recover to 2% by 2020.

US Actual (green) and Potential (yellow, source CBO) Output, logged. Source: FRED.

There seem to be two ways of thinking about this decline in potential output growth. One is that the slowdown in productivity growth was happening anyway, and has nothing to do with the global financial crisis and recession. This seems unlikely to be the major story. For the UK we have to rewrite the immediate pre-recession years as boom periods (a large positive output gap), even though most indicators suggests they were not. A global synchronised slowdown in productivity growth seems improbable, as some countries are at the technological frontier and others are catching up. As Ball notes, “in the countries hit hardest by the recession, the growth rate of potential output is much lower today than it was before 2008.” However the coincidence story is the one that both the OECD and IMF assume when they calculate output gaps or cyclically adjusted budget deficits. The CBO numbers for the US shown above adopt the coincidence theory to some extent, reducing potential growth from 3.5% in 2002 to 2.0% by the end of 2007.

If we stick to the more plausible idea that this is all somehow the result of the financial crisis and recession, we can again split explanations into two types: those that focus on the financial crisis and argue that crises of this type (rather than other types of recession) impact on potential output, and those that look at the impact of the recession itself. The distinction is important in understanding the impact of austerity. If the length and depth of the recession has permanently hit potential output, as Fatas and Summers suggest, then the cost of austerity is much greater than we could have imagined.

Looking at previous financial crises in individual countries, as Nick Oulton has done for example, does suggest a permanent hit to potential, but I have noted before that this result leans heavily on experience in Latin American countries, and Sweden’s recovery from its 1990 crisis suggests a more optimistic story. Estimates based on OECD countries alone suggest more modest impacts on potential output, of around only 2%.

What about the impact of the recession itself? Here it is helpful to go through the textbook story of how a large negative demand shock should impact the global economy. Lower demand lowers output and employment. Workers cut wages, and firms follow with price cuts. The fall in inflation leads the central bank to cut real interest rates, which restores demand, employment and output to its pre-recession trend.

We know why this time was different: monetary policy hit the zero lower bound (ZLB) and fiscal policy in 2010 went in the wrong direction. Yet employment has recovered to a considerable extent (although less so in the US than the UK). A recovery in employment but not output (relative to pre-recession trends) means by definition a decline in labour productivity growth. How could this happen?

The table below shows the rate of growth of real and nominal wages in the UK and US in pre and post recession periods.

US	2002-7	2008-15
Annual wage growth (1)	3.8%	2.1%
Annual price growth (2)	2.5%	1.5%
Difference	1.3%	0.6%
UK
Annual wage growth	4.5%	1.7%
Annual price growth	2.8%	2.1%
Difference	1.7%	-0.4%

1. Compensation per employee, source OECD Economic Outlook
2. GDP deflator, source OECD Economic Outlook

Nominal wage growth followed the textbook story. But price inflation did not fall to match, implying steadily falling real wages, particularly in the UK. This could just reflect the decline in productivity, which occurred either coincidentally or as a result of the financial crisis and recession.

The financial crisis could have reduced productivity growth if a ‘broken’ financial sector had stopped financing high productivity investment projects, or kept inefficient firms going through ‘pretend and extend’ lending. The recession could have reduced productivity growth by reducing investment, and therefore embodied [2] technical progress. Perhaps this loss of embodied technical progress occurs in all recessions, but we do not notice it because recoveries are quick and complete.

However the causality could be the other way around. Falling real wages led firms to switch production techniques such that they employed more labour per unit of capital. Workers priced themselves into jobs. The big question then becomes why did firms let this happen? Why did firms not take advantage of lower wage increases to reduce their own prices, and choose instead to raise their profit margins?

One story involves a secular increase in firms’ profit margins (Paul Krugman’s robber barons idea), either because of a reduction in goods market competition (profit margins are sometimes called the degree of monopoly), or a rise in rent seeking as Bob Solow suggests (HT DeLong). [3] However it is not obvious why this should be connected to the recession. If it is not, it is like the coincident and exogenous productivity decline. We will not get back to the earlier productivity growth path without reversing whatever caused this secular rise in profit margins.

Another, in some ways more optimistic, story involves different degrees of nominal rigidity: nominal wages are less sticky than nominal prices. As a result nominal wages led prices in reacting to the recession, but now prices are ‘catching up’ and profit margins will fall back. That would fit nicely with inflation continuing below target for some time, and real wages and productivity recovering. It is an optimistic story, because an additional demand stimulus would increase wage but not price inflation, and we would see rapid growth in labour productivity as firms reversed their earlier labour for capital substitution.

Unfortunately recent data suggests this is not happening. Instead core inflation is now above target in the US and rising to target in the UK.    

So is there some other way that a large recession in itself can cause a large reduction in potential output? Macroeconomists group such explanations under a general heading called ‘hysteresis mechanisms’: mechanisms whereby recent history can have permanent effects. Ball summarises the three main types of mechanism that economists have identified: “it appears that recessions sharply reduce capital accumulation, have long-term effects on employment (largely through lower labour force participation), and may slow the growth of total factor productivity.” If technical progress is embodied, we can link the first and last. That will be the subject of a later post.  

[1] For those not familiar with the term, a traditional way of thinking about potential output is that it is what output and incomes could have been if we had avoided booms and recessions, or equivalently if we had avoided domestically induced variations in inflation. Potential output can increase either because the labour force increases, or because labour productivity increases due to either technical progress and investment.

[2] Embodied technical progress is greater labour productivity brought about through new machinery i.e. it needs investment for it to happen.

[3] Postscript (just): Here is Martin Sandbu on the same issue