Showing posts with label macroeconomics. Show all posts
Showing posts with label macroeconomics. Show all posts

Wednesday 30 November 2022

The DSGE paradigm: Do Stop Generating Errors

From RBC to DSGE

The recent passing of Ed Prescott, the 2004 Nobel Laureate in economics, was a cause for sadness across the economics profession. Prescott was universally recognised as a revolutionary thinker in the field of macroeconomics and one of his great innovations (along with fellow Laureate Finn Kydland) was the introduction of so-called Real Business Cycle (RBC) models. In simple terms, these models postulate that business cycle fluctuations arise as a result of labour supply decisions in response to stochastic shocks. One of the consequences of this paradigm is that business cycles are optimal responses to productivity shocks and that interventions to offset such shocks are harmful because they cause the economy to deviate from its long-run optimal path.

The first attempt to produce an economic model based on these principles was Prescott’s 1986 paper ‘Theory Ahead of Business Cycle Measurement’ which was very much based on calibrated responses rather than one which used statistical techniques to fit the data. It was also a model which assumed a world in which there were no distortions. Unsurprisingly, Keynesian economists did not take the RBC conclusions lying down. They argued that the economy was characterised by frictions such as nominal rigidities, the existence of monopoly power and information asymmetries which can result in involuntary unemployment, thus opening up a role for governments to smooth the cycle. In response, the so-called New Keynesians devised a model paradigm which required the imposition of a number of restrictive assumptions in order to approximate the world as they saw it.

Thus did the literature on New Keynesian Dynamic Stochastic General Equilibrium (DSGE) models come into being: Dynamic because they operate over very long (infinite) horizons; Stochastic because they deal with random shocks and General Equilibrium because they are built up from microfoundations. Such models now dominate much of the academic thinking in the modelling and policy literature. But they are mathematically complex, opaque and founded on a series of assumptions that calls into question whether they have anything useful to contribute to the future of macroeconomics[1].

What’s not to like? Quite a lot as it happens!

In the words of Olivier Blanchard, “there are many reasons to dislike current DSGE models” particularly because of the apparently arbitrary nature of the assumptions on which they are based. For example, aggregate demand is based on infinitely lived households which are assumed to have perfect foresight. Show me one of those and I will give you some hen’s teeth. Furthermore, the inflation equation is based on a forward looking equation that does not take any account of inflation persistence. But perhaps the most contestable features of DGSE models is their slavish adherence to microfoundations. These attempt to embed economic behaviour patterns that are invariant to a particular state of the world. This allows macroeconomics to escape from the charge posed by the Lucas critique that the parameters of any model change as circumstances change – a criticism of the models in operation in the 1970s, and which was perceived to be one of the reasons why they performed so badly in predicting the recessions of the time.

There is a lot wrong with this way of thinking. For one thing, the microfoundations are based on the behaviour of representative agents. In other words, they impose a theory of how individual firms and households act and assume that we can scale this up to the wider economy. As one who grew up using models based on aggregate data, it has always struck me as odd that we should discard much of the richness inherent in the observational evidence of macro data. An interesting theoretical paper published in 2020 makes the more subtle point that for the representative agent to mimic the preference structure of the population requires the imposition of extreme restrictions on the utility function used to describe household behaviour. The supreme irony of this is that the DSGE revolution was able to capture the intellectual high ground because the structural modelling paradigm that it replaced was unable to counter the criticism levelled in Chris Sims’s classic 1980 paper that such models relied on “incredible” identifying assumptions.

A further thought is that we have little evidence that the utility functions of representative agents are invariant over time, as modern macro theory assumes. But whilst there is no doubt that the research underpinning the macro revolution in the late-1970s and early-1980s – including the influential work of Lucas – is intellectually persuasive, the evidence of this year alone, in which inflation spiked to 40-year highs unforeseen by most models in 2021, does not persuade me that the DSGE revolution has significantly enhanced the thinking in modern macro.

By this point you have probably gathered that I am highly sceptical of much of the work conducted in modern macro modelling in the last 40 or so years. This is not to deny that it is intellectually fascinating and I am more than happy to play around with DSGE models. But as Anton Korinek points out in this fascinating essay, “DSGE models aim to quantitatively describe the macroeconomy in an engineering-like fashion.” They fall victim to the “mathiness” in economics, of which Paul Romer was so scathing.

And their forecasting performance is poor

We might be more accepting of the DSGE paradigm if it produced significantly better forecasting results than what went before. The events of the past 15 years suggest that this is far from the case and it is now generally acknowledged that the out-of-sample forecasting performance of DSGE models is very poor. If this does not render them useless as a forecasting tool, it suggests that they are no better than the structural models which the academic community has spent forty years trying to knock down. Proponents will argue that this is not what they are designed to do. Rather they are designed to understand how the economy is constructed around the deep-seated parameters underpinning household and corporate decision-making which allows for policy evaluation.

This debate was brought into sharp focus recently following the publication of a fascinating paper on the properties of DSGE models which is less concerned about whether they represent good economics but whether they represent good models in a statistical sense. The answer, according to the authors, is that they do not. The paper can get quite dense in places but one of the things it does is to examine how well it can fit nonsense data. By randomly swapping the series around and feeding them into the DSGE model, “much of the time we get a model which predicts the [nonsense] data better than the model predicts the [actual] data.” They draw the damning conclusion that “even if one disdains forecasting as an end in itself, it is hard to see how this is at all compatible with a model capturing something – anything – essential about the structure of the economy.”

Last word

As one who for many years has used models for forecasting purposes that have been sniffily dismissed by the academic community, it is hard to avoid a sense of schadenfreude. Blanchard offers us a way out of this impasse, arguing that theoretical models of the economy have a role to play in “clarifying theoretical issues within a general equilibrium setting ... In short, [they] should facilitate the debate among macro theorists.” By contrast, policy models of the type with which I am most comfortable, “should fit the main characteristics of the data” and be used for forecasting and policy analysis. 

There is some merit in this argument. By all means continue to tinker with DSGE models to see what kinds of insight they can generate but do not let them anywhere near the real world until their forecast performance substantially improves. In the words of statistician George Box, “all models are wrong but some are useful”. And some are DSGE models.


[1] For an excellent introduction to many of the issues in modern macro, check out this free online textbook ‘Advanced Macroeconomics: An Easy Guide’ By Filipe Campante, Federico Sturzenegger and Andrés Velasco

Thursday 24 February 2022

Redrawing the economic map

As Europe awoke to the news that Russia has launched military action against Ukraine, it is hard to avoid the conclusion that the geopolitical tectonic plates have shifted. A war on this scale in continental Europe is not something we have seen since 1945 although we should not forget that the Soviet Union did invade Hungary in 1956 and Czechoslovakia in 1968, so there is a parallel (albeit inexact). Twenty years ago it all seemed very different. Having experienced a form of shock therapy following the collapse of the Soviet Union in 1991, which saw hyperinflation and a huge collapse in output, the Russian economy stabilised in the late-1990s. Accession to the G8 in 1997 gave rise to hopes that it would become a reliable international partner whose political and economic interests would be more aligned with the west. The annexation of Crimea in 2014 changed all that.

From a geopolitical perspective, Russia has become an increasingly difficult problem for the west to manage. To quote the British parliamentary Intelligence and Security Committee, “Russia is simultaneously both very strong and very weak.” It is a significant military player with a permanent seat on the UN Security Council. Yet it has a relatively small population compared to the west and a weak economy which is heavily reliant on hydrocarbon revenues. This makes it difficult to respond effectively. Military engagement by the west in Ukraine is out of the question, although matters could escalate if former Soviet Republics which are now NATO members (Estonia, Latvia and Lithuania) face a similar threat. That is something we would rather not think about. But as a response to the Ukrainian incursion, it is clear that the west will implement economic sanctions.

Germany has already paused its certification of the Nord Stream 2 gas pipeline. Whilst this does not mean that the pipeline will never be used, it is a significant move and will have major implications. Although Chancellor Scholz wants to wean Germany off imported Russian gas, the view in Moscow is this will be impossible in the short term and may not even be possible on a 5-10 year horizon. This is indeed plausible and the 2011 decision to end nuclear energy generation now looks rather ill-judged. However, now that the Greens are part of the government coalition, their resolve to further reduce dependency on fossil fuels should not be underestimated. Either way, this is likely to have significant costs for one or both parties – we cannot predict at this point where the incidence will fall.

How effective will sanctions be?

The German case was merely the most high profile of a range of sanctions introduced in recent days (the British government’s efforts were a particularly weak response) and more will be forthcoming. Sanctions are now regarded as the first response to aggressor nations and in contrast to the old maxim of “shoot first and ask questions later”, the Peterson Institute for International Economics (PIIE) acknowledges that “advance planning for the imposition of sanctions is now the norm.” But what are they designed to achieve? There are a range of possibilities. Sometimes they are simply implemented to satisfy domestic considerations rather than influence the actions of others; they may be designed to send a signal that the actions of others are unacceptable, or they may be intended to implement regime change. Whether or not sanctions are successful depends on which of these is the intention. 

A study by PIIE suggested that sanctions tend to be effective in roughly one-third of cases. But the success rate depends very much on the objectives. “Episodes involving modest and limited goals, such as the release of a political prisoner, succeeded half the time. Cases involving attempts to change regimes (e.g., by destabilizing a particular leader or by encouraging an autocrat to democratize), to impair a foreign adversary’s military potential, or to otherwise change its policies in a major way succeeded in about 30 percent of those cases. Efforts to disrupt relatively minor military adventures succeeded in only a fifth of cases.” The invasion of Ukraine is not a “minor military adventure” so the odds that sanctions will reverse the outcome are limited. In any case, as PIIE notes, “sanctions are of limited utility in achieving foreign policy goals that depend on compelling the target country to take actions it stoutly resists.” US efforts to promote political change in Iran and Cuba are testimony to this. Furthermore, according to PIIE: “It is hard to bully a bully with economic measures” since the evidence suggests that democratic regimes are more susceptible to such pressure than autocracies.

In order to manage expectations, western governments have to make it clear at the outset that they do not expect economic sanctions to facilitate regime change in Russia or reverse the Ukrainian invasion (although Putin did suggest in his speech that Russia does not intend to occupy Ukraine). What kind of sanctions could the west impose? The first option would be to sanction the free flow of Russian capital by imposing restrictions on those with close links to the government, the rationale being that pressure placed on Putin by power brokers would destabilise his grip on power. This would include restrictions on their personal activity and also the banks that they use.

There have also been calls to cut Russian access to SWIFT, the global interbank payments system. Whilst this would severely impact on Russian banks, European creditors would also struggle to get their money out of Russia. This would be particularly problematic since BIS data indicate that European banks hold the vast majority of foreign banks' exposure to Russia (chart above). Russia also has huge FX reserves, totalling around $630 billion, which would mean that it has no immediate need for market access to foreign currency. It also has its own financial payments system (SPFS) which funds around 20% of Russian settlements. However, the Atlantic Council think tank reckons that “the Russian equivalent of SWIFT remains mostly aspirational [and] is much ado about nothing,” concluding that its importance is overblown.

One concern is that sanctions on Russia could drive it further into China’s orbit as the two countries have become closer in recent years as they seek to weaken US hegemony. But China has to balance its relationship with Russia against its need to preserve relationships with the west and it has nothing to gain from any conflict with Ukraine. However, closer Chinese ties may weaken the impact of any economic sanctions that the west might impose (for example, if China were to become a bigger importer of Russian oil and gas).

Implications for the west

Thirty years ago much of the talk in policy circles was of the peace dividend that would accrue as a result of reduced defence spending. That dividend now appears to have been used up and recent events may force governments to think about raising defence spending. Only seven of the 30 NATO members currently spend more than 2% of GDP on defence – the benchmark which all members are meant to achieve by 2024. Increased defence spending will stretch public finances more than in the period 1945-90 because ageing populations mean that health services are a bigger competitor for tax revenue. It is therefore possible that taxation will have to rise in order to pay for it.

More generally the era of peace, prosperity and openness characterised by increased globalisation is apparently in retreat (see the KOF index). Russia may not be the superpower of old but it is big enough to cause problems if it flexes its muscles. China waits in the wings, perhaps assessing the west’s response to the Ukrainian invasion as it ponders how to deal with Taiwan. For those of us old enough to remember the Cold War, none of this is new. Nor does it necessarily mean huge changes in the way we live our day-to-day lives. But governments will have to make increasingly difficult choices about resource allocation as we revert to a world of “them and us.”

Tuesday 15 February 2022

The Magic Money Tree

Modern Monetary Theory (MMT) is back in the headlines following a recent piece in the New York Times (here). In truth, the article is more a profile of one its best known proponents, Professor Stephanie Kelton of Stony Brook University, than an attempt to examine MMT. Mainstream economists have nonetheless queued up to criticise it, probably because the original headline was titled “Time for a Victory Lap” (it has since been changed to “Is This What Winning Looks Like” so the subeditor has a lot to answer for). However, the article still contains the phrase “Kelton … is the star architect of a movement that is on something of a victory lap”. This has enraged the mainstream economics community because far from enjoying a victory lap, MMT remains untried, unproven and untestable.

A lot has happened since I first looked at the subject three years ago: Kelton’s book The Deficit Myth has become a best seller whilst the pandemic has focused minds on the role of government deficits. This fascinating area is thus worth revisiting. However, the quip that Modern Monetary Theory is not modern, is not about money and is not a theory still holds true. It is not modern because it has its roots in Abba Lerner’s Functional Finance Theory which first saw the light of day in 1943 and which suggests that government should finance itself to meet explicit economic goals, such as smoothing the business cycle, achieving full employment and boosting growth. It is also more a fiscal theory than a monetary one. At heart it is based on the premise that since the government is the monopoly supplier of money, there is no such thing as a budget constraint because governments can finance their deficits by creating additional liquidity at zero cost (subject to an inflation constraint). It is most definitely not a theory about how the economy works. Instead it is closer to a doctrine to which its adherents passionately adhere whilst regarding non-believers as having not yet seen the light (or worse, economic heretics).

What particularly riles the mainstream community is that there is no formal model which can be written down and therefore no testable hypothesis. In the words of blogger Noah Smith, “MMT proponents almost always refuse to specify exactly how they think the economy works. They offer a package of policy prescriptions, but these prescriptions can only be learned by consulting the MMT proponents themselves.” This is particularly irksome because it allows MMT proponents to sidestep the criticisms of the doctrine, of which there are many.

Many of these criticisms centre around the role of money, upon which the fiscal analysis is founded. For example, it treats money as being primarily created by the state (defined as the government sector plus the central bank) and has little or nothing to say about the role of banks in the process. It also treats money as a public good which should be used to maximise social welfare rather than its more prosaic use as a medium of exchange. This in turn assumes there is only one form of money in the economy, but as I have pointed out before this is not the case. Domestic actors may choose to use foreign currency, for example, or opt for digital options. Thus, although governments can create money almost without limit, there is no guarantee that demand will match supply. Increasing supply way beyond demand will only lead to currency debasement. In an excellent paper by the Banque de France[1] (here) the authors do a good job of picking holes in the theoretical underpinnings of MMT, noting that none of its supporters acknowledge “the reason modern literature on money puts  forward for what makes legal currency “acceptable” by the public, i.e. monetary policy credibility.”

Whilst MMT does rest on shaky theoretical foundations, it is not the only area in modern macroeconomics to suffer from such problems. The New Keynesian school, which is the predominant model used by central banks, assumes no role for the quantity of money. It also imposes perfect pass-through from the policy rate to all other rates in the economy, thus giving the central bank a powerful lever to affect intertemporal decisions, which is extremely questionable. Nobel Laureate Joseph Stiglitz published a paper in 2017 which argued that “the DSGE models that have come to dominate macroeconomics during the past quarter-century [apply] the wrong microfoundations, which failed to incorporate key aspects of economic behavior. Inadequate modelling of the financial sector meant they were ill-suited for predicting or responding to a financial crisis; and a reliance on representative agent models meant they were ill-suited for analysing either the role of distribution in fluctuations and crises or the consequences of fluctuations on inequality.”

It is thus perhaps a little unfair to single out MMT which has fallen victim to the fetish for quantification in economics. Current academic practice seems to believe that if something cannot be quantified it is not a valid explanation of how the economy works. It is instructive to remember that the ideas of Keynes, which came to dominate the agenda after 1945, were also subject to significant criticism following their publication in the 1930s. Nonetheless there is a lot wrong with MMT and I concur with the conclusion to the BdF paper: “Such a stark contrast with mainstream economics analysis and recommendations would be understandable if MMT economists engaged into a debate with their colleagues to explain and justify their positions, from both a theoretical and empirical point of view. However, they rather prefer to talk between themselves, repeating consistently the same ideas that others formulated in a distant past, disregarding facts and theories that do not fit into their approach, and accusing those who do not share their ideas of being incompetent.”

Yet despite all these reservations MMT has opened up a debate about the role of government both during and in the wake of the pandemic. One of the core ideas of MMT is that governments are not like households because they have an (almost) infinite life and therefore debt can be repaid over periods extending over many generations. There is thus no rush to impose significant fiscal tightening as the economy recovers from the Covid shock. This view is, of course, not unique to MMT: It is a standard element in fiscal dynamics but it is a lesson that governments should heed as the rush to take away support after the pandemic gathers momentum.

If it has opened the eyes of politicians to the uses of fiscal policy after decades in the doldrums, then maybe MMT has served a useful function. But a policy of near unlimited fiscal expansion is for the birds. It calls to mind the other acronym often applied to MMT: The Magic Money Tree.


[1] Drumetz, F. and C. Pfister (2021) ‘The Meaning of MMT’, Banque de France Working Paper 833

Wednesday 20 October 2021

No expectations

Inflation remains one of the big items on the policy agenda with the IMF’s latest World Economic Outlook devoting a considerable amount of space to the topic, warning that “central banks should remain vigilant about the possible inflationary effects of recent monetary expansions.” In fairness the IMF does use the stock phrase beloved of policy analysts that “long-term inflation expectations have stayed relatively anchored.” However this comes at a time when parts of the macroeconomics profession are beginning to question just how much we really know about the inflation generation process, with the role of expectations coming under particular scrutiny.

Like many areas of economics the forces underpinning inflation have been subject to various fads over the years. Between the 1950s and 1970s, attention focused on the labour market and the role of the wage bargaining process. During the 1980s monetary trends were the flavour of the period but over the last 25 years the main area of focus has been the deviation of output from the NAIRU and the determination of inflationary expectations. Given the change in fashions over the years, it is difficult to take seriously the idea that there is a generic theory of inflation: like theories of the exchange rate, different factors drive the process at different times.

For my part, I have long harboured doubts about the way macroeconomics treats inflation (see the posts Do we know what drives inflation? from August 2017 and Monetary policy complications from October 2017 for more detail). It was thus heartening to see that economists at the Federal Reserve share similar reservations. In a highly readable paper published last month, which received considerable media exposure, Jeremy Rudd of the Fed staff posed the questionWhy do we think that inflation expectations matter for inflation? (and should we?)

As the paper’s abstract noted, “A review of the relevant theoretical and empirical literature suggests that this belief [in expectations] rests on extremely shaky foundations, and a case is made that adhering to it uncritically could easily lead to serious policy errors.” Rudd goes on to describe competing models of inflation used by macroeconomists over the past 50 years and concludes that the use of expectations to explain inflation dynamics is both unnecessary and unsound. In his view it is unnecessary because it can be explained more readily by other factors and unsound because it is not based on any good theoretical and empirical evidence. Moreover, the theoretical models are influenced by short-term (usually one period ahead) expectations, which “sits uneasily with the observation that in policy circles … much more attention is paid to long-run inflation expectations.”

The empirical evidence suggests little evidence of a direct effect of expectations on inflation. According to Blinder et all (1998)[1], “what little we know about firms’ price-setting behavior suggests that many tend to respond to cost increases only when they actually show up and are visible to their customers, rather than in a pre-emptive fashion.” Evidence from the Atlanta Fed survey of business inflation expectations over the past decade confirms that expectations have been remarkably constant until relatively recently with unit costs one year ahead generally expected to grow at an average rate of 2% (chart). However, it is notable that during 2021 there has been a sharp pickup as the economy suffered bottlenecks in the wake of the pandemic.

The standard central bank view of inflation expectations was highlighted in a 2019 speech by BoE MPC member Silvana Tenreyro. It is a perfectly fine piece of conventional economic analysis as befits an orthodox central bank economist. She noted that household inflation expectations are a key input into the BoE’s thinking, arguing that for any given interest rate, higher inflation expectations increase households’ incentive to spend today rather than saving. But once you start digging below the surface, the argument rests on some weak foundations. For example, the evidence from both the US and UK suggests that households consistently expect CPI inflation to average close to 3% at horizons of between one and five years ahead. In other words, despite the best efforts of central banks, households continue to expect inflation to run above their target rate. Tenreyro was also forced to concede that “households do not always adjust their expectations even when prices start rising more quickly or slowly than they had expected” which really ought to raise some questions about their usefulness.

A more serious criticism of inflation expectations came from Rudd who pointed out that “the presence of expected inflation in these models provides essentially the only justification for the widespread view that expectations actually do influence inflation … And this apotheosis has occurred with minimal direct evidence, next-to-no examination of alternatives that might do a similar job fitting the available facts, and zero introspection as to whether it makes sense.” Instead Rudd offers the explanation that the absence of a wage-price spiral is one of the key defining features of recent inflation dynamics. He goes on to suggest that “in situations where inflation is relatively low on average, it also seems likely that there will be less of a concern on workers’ part about changes in the cost of living … But this is a story about outcomes, not expectations.” In other words, when inflation is below a certain threshold level workers stop pushing for bigger wage hikes which has contributed to keeping inflation low – unlike in the 1970s.

This has a number of important policy implications:

  • First, it will be important to keep an eye on whether wage settlements are responding to higher price inflation. 
  • Second, because central bank economists, who are influenced by latest academic thinking, generally tell policymakers that “expected inflation is the ultimate determinant of inflation’s long-run trend, [they] implicitly provide too much assurance that this claim is settled fact. Advice along these lines also naturally biases policymakers toward being overly concerned with expectations management, or toward concluding that survey- or market-based measures of expected inflation provide useful and reliable policy.” 
  • Third, precisely because inflation dynamics are influenced more by outcomes than expectations, “it is far more useful to ensure that inflation remains off of people’s radar screens than it would be to attempt to “reanchor” expected inflation.” 
  • Finally, “using inflation expectations as a policy instrument or intermediate target has the result of adding a new unobservable to the mix. And … policies that rely too heavily on unobservables can often end in tears.”

Even if you do not accept Rudd’s premise (and many mainstream economists do not) this is an important contribution to the debate. One of the criticisms being bandied around as the economy rebounds from the 2020 collapse is that there is insufficient diversity of thinking around some of the key underpinnings of mainstream macro. If nothing else, Rudd forces us to think more critically about how we think of inflation and our understanding will be all the stronger for it.


[1] Blinder, A., E. Canetti, D. Lebow, and J. Rudd (1998). ‘Asking About Prices: A New Approach to Understanding Price Stickiness’. New York: Russell Sage Foundation.

Monday 9 November 2020

Markets keen on the vaccine

2020 has proven to be the year from hell, yet two pieces of good news have today given markets a rocket-propelled surge. Markets were overjoyed enough with the news that the uncertainty surrounding the US election is effectively over but the news that a promising vaccine has been developed against Covid-19 sent them into ecstasy. The vaccine has been developed by Pfizer Inc. and BioNTech and is 90% effective, according to the manufacturers. It is obviously very early days to be talking about a solution to the pandemic which has produced the biggest collapse in global activity in 90 years. The vaccine may yet prove to be a damp squib, and it will not prevent the next few months being exceptionally difficult for the European and US economies. But it does represent a potential game changer. 

Market implications 

In terms of the market reaction the FTSE100 today recorded its 17th largest daily increase on data back to 1984 (9437 observations); the rise in the CAC40 was the 10th largest on data back to 1969 (13528 data points) whilst the IBEX recorded its 6th biggest increase since 1987 (8829 observations). That said, all three markets remain heavily underwater for the year (chart). Interestingly, sectors which have been particularly badly ravaged over the past six months have been amongst the strongest performers. The stock price of International Airlines Group rose by 25% in the course of today, although it is still 70% below the 2020 peak recorded in January. By contrast, companies whose business model has thrived during the lockdown have underperformed. Ocado Group Plc, which provides grocery home delivery services, was down 12%. On the other side of the Atlantic, Zoom’s price was down 14% at the time of writing and even Amazon was down 2%. All this strikes me as a little premature. A lot of international business meetings will likely continue to be conducted via Zoom rather than people jetting off for a one hour face-to-face as companies continue to bear down on costs.

Whilst it may be a little early to swap your Zoom stocks for IAG, there is some method in the market madness even though it is questionable whether it should be factoring in all the good news immediately. A combination of extremely low interest rates and the prospect of an economic recovery ought to support equities in the medium-term. Accordingly investors may reduce some of their exposure to safe haven assets such as fixed income and gold and position into equities, although a prudent investor who missed today’s rally may be advised to buy on the dips since some of today’s gains will undoubtedly be given back before long. 

Economic implications 

The prospect of a vaccine has major economic implications. After all there is a lot of pent-up demand which has been postponed since the spring. But the vaccine is nowhere near ready for widespread use and even if it does get approval before year-end, as has been suggested, it is unlikely to be widely available until the second half of next year at the earliest. Accordingly the impact on the wider economy is unlikely to be felt before 2022. Over the coming months governments will thus have to continue providing support to those who have lost their jobs or whose jobs are at risk. But the prospect of a vaccine changes the calculus by resolving the duration mismatch problem which governments have faced in the course of this year.

Whilst governments want to provide as much support to the economy as possible, they are also acutely aware of the costs The UK government has in recent months been particularly hesitant to open the taps further. Only last month Chancellor Rishi Sunak suggested thatwe have a sacred responsibility to future generations to leave the public finances strong and … this Conservative government will always balance the books.” But if a vaccine is in the offing governments will not face an open-ended commitment to provide fiscal support: They can act in the near-term with a high degree of confidence that an economic recovery lies ahead.

This does not change my long-held view that there will be a considerable degree of economic scarring. It is highly likely that the pandemic will prove to be a watershed for the economy. Part of the change in economic behaviour observed over the last eight months will prove to be permanent with the result that there will be a period of resource reallocation as the economy transitions to a new structure. Such an outcome could be driven by a change in tastes (e.g. a preference for online shopping rather than physical shopping, which will have major implications for the retail sector). This in turn will almost certainly result in frictional unemployment which will take some time to be eliminated. It could also mean that the sectoral distribution of capital which prevailed prior to the pandemic will have to be significantly changed, implying a faster rate of capital scrapping in those areas where it is no longer required which turn will depress the economy’s potential growth rate (at least temporarily).

The UK will find itself in a worse position than other European economies. It is becoming increasingly evident that the form of Brexit the government is intent on delivering will be a much harder variant than imagined even a year ago (I will come back to this in a future post). Accordingly it is likely that even in the absence of the restrictions imposed by Covid-19 the UK will take longer to get back to pre-recession levels of output than elsewhere.

For all today’s optimism there is still the potential for the path out of the pandemic to prove torturous and uneven. However it represents the first piece of genuinely good news in the fight against Covid-19. As The Queen put it in her April broadcastwhile we may have more still to endure, better days will return: we will be with our friends again; we will be with our families again; we will meet again.” But as the old song has it, “Don’t know where, don’t know when.”