3 paths forward for the economy

The pandemic is affecting the entire world, but we are seeing very different approaches to dealing with it in different countries. I have identified 3 broad strategies each of which will have very different outcomes in terms of the economic outlook. In this post I am not looking to evaluate the approaches from an ethical or public health perspective, but purely on what the likely economic results will be.

Path 1 – Control the Virus e.g. New Zealand

This is the approach I have been advocating and which I spoke about on my recent IAN talk. Please click below if you are interested in watching.


This approach has been very successful at controlling the virus in some countries such as New Zealand, Norway, Singapore, China and Australia. All of these countries now have low levels of infection and can look at a material reopening of their economies. Other countries have been trying to play catch up, are past the peak in their infections and are maintaining lockdowns until the level of infections comes to a low level. This group of countries includes Canada and most of the EU.

This has not been an easy path to follow and for it to be successful it does not only take the good public policy but also it critically requires huge public support for measures which involve massive changes in behaviour. The countries that have been successful have given clear and detailed public health messages which have been adhered to due to high levels of public support and trust in the country’s government and institutions.

The economic impact of COVID has been very severe but these countries are the most likely to hope to experience COVID as being economically similar to a natural disaster and see a sharp rebound in economic activity. Bernanke, ex-Chairman of the Federal Reserve in the US, likened COVID to a snowstorm. In a snowstorm, we halt much of the economic activity but once the snow melts, we can go back to how we were before.

Waiting until the level of infection is very low has two big economic benefits

  1. The number of people infected is low, which means that anyone you interact with is highly unlikely to have the virus and so all the allowed activities are in effect very safe. This means people are confident to go back to work and do the allowed activities as you reopen.
  2. There is room to experiment with the reopening and how it impacts R0. If the impact is larger than you expected for an activity, then you have time to reverse the policy as the absolute number of infections remains very low. There is no danger of the virus getting out of control quickly.

With COVID the world will not be the same as before, but it may be possible to reopen large parts of the economy while keeping the rate of transmission and level of infections low.

Path 2 – Herd Immunity e.g. Sweden

I have used Sweden as my example but at the moment, to be honest, it is my only one and is a global outlier. It is the only country I know which has chosen to follow this path with high public approval and consent which makes all the difference to the potential economic outcome.

The choice to manage the spread of the virus with the longer-term goal of herd immunity is clearly possible. The economy is not shocked by the strict lockdowns and only a milder form of restriction is made to slow rather than to reduce the virus. Sweden has high levels of public support with 70% of the population supporting its government’s approach. With public trust and support the economy continues to function with a far milder slowdown in economic activity.

The data from the antibodies tests in Stockholm last week were broadly in line with my expectations but completely shocking to the Swedish authorities. With only 7.3% of Stockholm residents testing positive for the antibodies we can imply a mortality rate of 1.5-2.0%. This is slightly higher than the results from New York, France, Spain and the UK which all suggested 1.0-1.5% but I would suggest is within a margin of error given the relatively small sample size.

From outside Sweden we might think that this result would lead to a change in policy and a dramatic fall in public support but so far this does not seem to be the case at all. This implies that Sweden is uniquely happy to follow this route and I cannot say that the economic outcome should be poor. Whether it is better or worse economically than the path chosen by other countries such as Norway is not clear yet, but I see no reason to think it materially better or worse.

While I said that Sweden is my only example of herd immunity with broad public support it is not my only example of a country pursuing this strategy. A good example is Brazil where the government under Bolsonaro has deemed COVID to be “a little flu” and will not pursue any public health measures. But the population is not supportive of this plan which will lead to severe economic disruption. Without consent the population is afraid and so its behaviours change, both on the supply side as people do not want to go to dangerous workplaces, and on the demand side as a lack of confidence leads to a decline in spending and investment.

It is important to note that from a public health perspective Path 2 is the default strategy. Anything less than a strongly concerted effort to control the virus will make it continue to spread and grow. But going down this path with consent like Sweden has a very different economic outcome to doing it without consent.

Path 3 – Neither of the above e.g. UK, US

This occurs when there is a major divide between those who want to follow the two paths above. A majority of the population would prefer to take Path 1 and control the virus but a significant minority, including the government, prefer Path 2 to reopen the economy even if the virus is not controlled. This is the situation in the US and increasingly clearly also in the UK.

For both the US and the UK we went into lockdown late, made the lockdown not very strict and are moving to ease restrictions before the level of infection is low and declining. There has been some attempt to control the virus, but it has been half-hearted and thus ineffective.

Trump gets pretty uniformly panned in the UK for his approach but in a way, it has a certain brutal honesty to it. He does not really pretend that he cares about public health, he is very clear that he cares about the economy. He does not argue that it is safe to reopen, he argues that the economy comes first. The US public has a majority in favour of controlling the virus but has a significant minority that strongly prefers Path 2. Those people are also Trump’s support base and so politically it should not be surprising that he is pursuing a policy path which they support even if a majority of the broader country do not. Trump has never really been a President who wanted to govern for everyone, he governs for his base and his interests. It remains to be seen if he can generate widespread support for his approach.

The UK political landscape is somewhat different. We have a clear majority in favour of following Path 1 but again a significant minority who prefer Path 2. Looking at the opinion polls I do not see the strong divide in the country we had with Brexit. 73% of the UK population wants clear advice with detailed guidance, not the muddling appeal to “common sense” that we are getting. It is true that Conservative voters, Leave voters and older people are more likely to want to reopen earlier but there is a majority in all categories for a focus on public health and caution on reopening. But importantly the relatively small minority who are very keen on a rapid reopening are the small subset who are the type of people who are members of the Conservative Party and also the type of people who are Conservative MPs and in government.


I am sure there are many in the UK government who passionately want to follow Path 1, perhaps after his ICU experience that even includes Boris Johnson. But we also have Dominic Cummings who showed what he thought of the “Stay at Home” slogan by travelling 250 miles to Durham, and Rishi Sunak who is arguing for a swift reopening.

The effect of a split in government and a lack of clear direction is that the default strategy of letting the virus run away again becomes the effective policy. This is in effect the same policy that Trump has adopted but confusingly the rhetoric is entirely the opposite. When Trump argues for reopening, he talks about individual liberty and the economy. When the UK government argues for school reopening it does not say what everyone knows i.e. it is an economic priority. Instead, Gove tells us it is “safe”, and Williamson uses emotional blackmail on teachers to tell them their pupils need them. This contradiction between rhetoric and reality leads to further erosion of public trust.

To follow Path 1 the government needed to build a consensus in early March for measures which the public initially did not think we needed. It could still attempt to use the majority support for prioritising public health now to try again to make more effective policy. Instead, it is using the rhetoric of public health to sell the policies of reopening. Even now the slogan is

“Stay Alert – Control the Virus – Save Lives”

This is a slogan for Path 1. But all the policies are moving towards Path 2. I do not think this has a good outcome. The result will not be the economic recovery they hope for as without trust and security our confidence is so impaired that no recovery is possible.

If we combine the rhetoric of a government focused on controlling the virus, with the actions of a government that will not do so, I expect to see both a rising infection rate and also a misfiring economy. In this case, perhaps the government will admit its mistakes and refocus on being effective in controlling COVID. Or perhaps they will claim they have done everything they can, that controlling the virus was not possible as people did not “Stay Alert”, and we should move down Path 2.

Which of those sounds more in character for this government?

Does policy matter?

It is all too easy to become fatalistic when faced with a massive problem like COVID-19. One could just assume that there is nothing we can do; all the deaths and economic destruction are inevitable and we just have to get on with things. I do not agree. Good policy is possible and the contrast between the approach of the UK and NZ is a useful demonstration of this.

The chart below compares actual daily deaths in the UK (orange) with a projection for the next few months (blue). The timing and size of the initial peak were dictated by the decision to go into lockdown on March 23rd. As inputs to the projection, I allow R0 to stay around 1 for a few weeks and then creep up to 1.3. From early June daily deaths begin to rise rapidly again; if we want the next peak to be at a similar level to the last, then a further lockdown will be required soon.

As an alternative scenario, let’s look at the model if we had gone into lockdown on March 9th. This was the date that Italy went into lockdown whereas here in the UK, Boris Johnson spent the Daily Briefing explaining that he was still shaking hands with everyone, including COVID patients in hospital.

Blue again is the model, this time based upon the earlier lockdown assumption; orange actual deaths in the UK. The difference may appear shocking but comes directly from the exponential growth of virus cases. As opposed to peaking around 1,000 deaths, we would have peaked at below 200. Rather than the current many hundreds of deaths per day, we would have perhaps 10.

This exponential growth has some simple intuition around it. Early on during the 2-week period when we were told to wash our hands, but not to socially distance or stay home, I estimate R0 to be 2.0. R0 of 2 means the number of infections doubles every 5 days – therefore in 2 weeks the number of infections would double 3 times i.e. 2, 4, 8 –2^3. If instead the R0 were 0.8, then the number of people infected would change by a factor of (0.8)^3 – which is to roughly halve. Comparing these, entering lockdown earlier would have halved cases rather increasing by a factor of 8 – a total of a 16-fold impact on the number of cases. This is why the blue line above is so much lower than the orange line.

The impact of this decision has not just been seen in the extra tens of thousands of deaths, it also makes a huge difference in how we can loosen the lockdown. In the projection above, I still assume a post lockdown R0 of 1.3. If the overall level of infections is much lower, then in absolute terms the growth in the virus is hugely lower. This would mean we would have far more room to experiment with lockdown easing measures such as school reopening without risking an imminent large outbreak.

This scenario shows to me that policy choices really matter. The example of NZ where they did exactly this shows that it is possible in the real world. They went into lockdown BEFORE they had their first death from COVID. The infection levels were low and now they have effectively eradicated the virus with a total of 21 deaths. This is why the UK government does not want to talk about international comparisons or mistakes they have made. We had plenty of warnings and examples from other countries on what we should do, but the UK has made catastrophic policy decisions that have cost tens of thousands of lives and made it hard to contemplate the removal of the lockdown. However, we do not have to continue making terrible decisions and better policy is possible.

Model update

We have had some higher quality data recently which we can use to compare to my model assumptions and projections

Update on Mortality Rate

I used 1% in my models from early April. This still looks a good estimate but now I think rather than the range being 0.5-1.0% it is perhaps 1.0-1.5%

The reason is that we now have had 3 high quality pieces of data from large samples of people from areas of high infection to see how many people have been infected. I have already written about the New York results which suggested something a little over 1% mortality rate. Spain found that 5% of its population have had it and France 4.5% In Spain this result means that if we just take the raw COVID death data we have a mortality rate of 1.1%. If we take a more reasonable assumption that this data is underreported and use the excess death data instead then the true Infection Mortality Rate would be perhaps 1.4%.

I used the updated mortality rate of 1.1% to relook at the path of deaths in Spain and from that estimate what R0 must have been.

To get this fit we need an R0 of close to 3 early in the infection, dropping to 2 as people became aware of the pandemic and then to 0.8 after the lockdown on March 13th. This is the same as my models from last month.

Update on R0

Public Health England has recently suggested that the overall R0 in the UK is currently just below 1 which is a combination of being far below this in London (perhaps 0.4) and likely above 1 in other parts of the country such as the North East.

Source: FT

Since we are relaxing lockdown it seems reasonable to project that the R0 will rise from here. In the projection below I have put the future R0 at just 1.2 and if we want the next peak in deaths to be the same as the last one then we would need to go into lockdown in early July i.e. about 6 weeks’ time. Then we would come out of lockdown again in early September i.e. we spend more time in lockdown than we do in periods of minor easing and we never reach Boris’ Phase 2 of further easing of lockdown restrictions.

Is there a more optimistic projection?

To be much more optimistic we need to find a way to limit transmission without going back into lockdown. We must find more targeted ways to change behaviour rather than the very blunt tool of making us all stay inside our homes. This could be Test, Trace and Isolate or better public information on how to limit transmission.

How else could the projection be changed?

The simplest way is that policy is different. If lockdown becomes more severe then the R0 never rises and deaths keep falling. If instead we choose to carry on along Boris’ path of further lockdown relaxation then the R0 would be higher again and the number of deaths would rise far more rapidly. If we choose not to go back into lockdown then the number of deaths just keeps rising exponentially.

What is safe?

As expected, many countries are now relaxing their lockdowns as case numbers and deaths move past the peak. In the UK on Sunday, the PM took 15 minutes to explain what was going on although spectacularly failed to explain anything. The debacle, watched by 30 million people, has left us with vague and often contradictory public health messaging about how we should all behave, which is the worst possible approach.

This article provides a summary of the advice and attempted “clarifications” from the past 3 days: https://www.huffpost.com/entry/how-boris-johnsons-stay-alert-message-unravelled-in-24-calamitous-hours_n_5ebb4d71c5b6b58e4cc98f7c

With the government failing to provide credible expert guidance, we have been left largely on our own. Tempted to rely on our “common sense”, humans are terrible at intuitively understanding risk, especially where statistics and brand-new problems are involved. We love to draw analogies e.g. “it is just a flu” even if these analogies are not very good. My approach is to research the virus as much as I can and share my current thinking on what I’m doing to stay safe.

I have been disappointed by the output from governments, health bodies and academia, but have found a few bright people able to communicate the science. Prof Erin Bromage of Dartmouth University is excellent, and I have incorporated much of his recent post in my thinking. https://www.erinbromage.com/post/about-the-author-professor-erin-bromage

Please be careful and do not imagine I am giving you all health advice or that there is certainty on any of these items. This is simply my current understanding of the science and how it applies to behaviour.

How the virus is transmitted

My understanding of how we become infected through surfaces has not changed very much and I have nothing to add to the official guidance. The advice on handwashing and not touching your face, combined with regular cleaning of surfaces seems a highly sensible way to reduce the risk of transmission.

I have changed my thinking around infection through the air. It seems that most cases of transmission come via the air rather than surfaces and given this is the main risk it should be the focus of our public health advice on return to work as it is much harder to manage as an individual. In particular the risk comes from aerosol i.e. the very small particles which last far longer in the air and move further than the 2m social distance guidelines.

Initially I made the mistake of thinking that viral transmission is a bit like a game of tig – if you got too close to an infected person you were “it”. It is often portrayed that you are safe from being “it” or safe from infection if you stay more than 2 metres away from other people, “social distancing”. The more I have read, the more this seems a poor metaphor for the transmission of a virus.

To become infected with a virus, there is a threshold number of virus particles required to enter your system. If there are just a few particles, then your immune system recognises them, bats them away and you are not infected. If there are many, the system is overwhelmed, and the virus freely replicates.

This number must vary by person but let’s assume a threshold of 1000 particles as a reasonable benchmark. Your risk of infection is determined by the number of particles in the air and how long you are exposed for:

Infection = Exposure x Time

If your exposure were 50 particles per minute and you spent 20 minutes in that environment, then you would reach the threshold of 1000 particles and be at serious risk of infection. Higher numbers of particles in the air or longer exposure both of course lead to higher risk.

How many virus particles does an infected person put into the air?

Initially let’s assume we are outside in good airflow and let’s ignore how long the particles stay in the air. The number of particles released by an infected person will vary depending on whether the person is:

  1. Breathing
  2. Speaking
  3. Heavy breathing/singing
  4. Coughing/sneezing

Considering each in turn:

  1. Breathing– not very risky

There is a low amount of viral material, perhaps only 3-20 virus RNA copies per minute. In addition, the water particles you breathe out upon which the virus sits are low velocity and so drop to the ground quickly. This means that even without good social distancing it would take a long time to become infected perhaps many hours, so in this situation social distancing should be very effective.

  1. Speaking – more risky

Speaking generates as many as 10 times as many droplets as breathing i.e. up to 200 per minute which means we could reach our 1000 particle threshold in as little as 5 minutes. Of course, in most conversations we each speak about half the time with pauses, so it seems more reasonable to think of 10-15 mins as a reasonable threshold for dangerous exposure levels. Here the good news is that the velocity of the particles is again low and so social distancing of at least 2m should be effective. Adding more distance of course, would make this even safer and so extended conversation outdoors should be safe.

  1. Heavy breathing/singing – be far more careful
    Playing sport or singing in a choir is significantly more dangerous than simply breathing or speaking. Here the number of particles and their radius of spread is far greater. If someone is simply walking past, then the time of exposure is so short so as to not be too risky, but any activity where you are within a few metres for an extended period will be dangerous.
  2. Cough and sneeze – very risky
    The number of virus particles expelled in coughs and sneezes is enormous and they travel at high velocity so social distancing will not protect you as the particles will go a lot further than 2m. If someone is coughing or sneezing, then you simply have to try to be nowhere near them and hope they sneeze in the other direction.

What does this mean for what we can safely do?
For both breathing and speaking, it takes time to get a dangerous level of exposure and social distancing outside will work. Passing people in the street or someone running past you is not dangerous and I feel less paranoid about passing contact with strangers. I can also be quite confident about talking to people more than 2m away outside, especially in the sunshine, where UV does a fantastic job of killing the virus in the air and on any surface.

But this is notably different from the current government advice which has been very restrictive on people having socially distanced interactions outside in the sunshine. It seems now you are allowed to sit 2m away from people outside but only if you don’t know them. I have found there to be a large difference between what I think is safe and the current government advice. They are still very restrictive on outdoor activities I think are safe and promoting indoor activities I think are still very dangerous.

What about Indoors?

The situation indoors is very different from outdoors and inherently riskier. Let’s consider 5 risk factors:

  1. Type breathing (normal breath, speaking, heavy breathing, cough, sneeze)
  2. Number of people
  3. Size of space
  4. Amount of ventilation
  5. Length of time

As described above socially distanced breathing and speaking are lower risk, but in an enclosed space, particles will continue to circulate in the room so you will not be protected from prolonged exposure. The guidance today from the government on workplace safety, suggests that simply having workers and commuters at least 2m apart on trains and offices will provide a significant level of protection. I do not think this is true.

Here is a sample office floorplan with social distancing, courtesy of WeWork

Here we have an example of an office with people all 2m apart and no open windows. The air in the room will slowly circulate and everyone in the room will receive a high level of exposure.

There are well documented examples of where this has happened. The restaurant below had airflow from right to left and over a 90-minute dinner, Diner A1 infects many people even at other tables, well beyond the 2m threshold.

This example from a call centre is even more compelling.

From only one infected employee over a single week, we see very high level of infection (note only 2 out of 94 infected were asymptomatic). The air circulates around the room over a long period and they are all exposed.

The issue of airflow distributing infection is certainly well known in the medical profession. The following diagram is from the Department of Health HTM 01-05 and shows how instruments and people should move in a sterile environment. But government are not recommending this concept being applied to other workplaces.

Simple advice on a 2m separation indoors is far from sufficient, but this has been overwhelmingly the focus of the government’s return to work advice. If a simple 2m rule indoors is not enough, then we need to better understand what matters and how to make indoor spaces safer. Simply opening public transport, offices, restaurants, and cinemas with social distancing is not going to work.

I would like to find research which gives parameters to turn the risk factors above into an operational risk model.

For example

Normal office

20 people, 140 sqm, speaking, low ventilation, 8 hours = what risk level?

Socially distanced office:

10 people, 140 sqm, speaking, low ventilation, 8 hours = what risk level?

How about a squash court?

2 people, 60 sqm, heavy breathing, low ventilation, I hour = what risk level?

I imagine that the relationships are non-linear and non-intuitive which means I cannot say how much safer a socially distanced office is from a normal one. Nor can I be confident if they are safer or worse than an hour of squash – one could easily be an order of magnitude more dangerous than the other. I need a lot more information before I can make good risk decisions.

Next Questions

Even though our government has given up we cannot.

  • How far do particles travel and how long do they stay in the air? https://www.youtube.com/watch?time_continue=39&v=WZSKoNGTR6Q&feature=emb_logo
  • Size of particles: amount of virus, travel, persistence, types of breathing
  • If someone else has been in a room for an hour how long should I wait before I enter it?
  • Does aircon and airflow make it worse by distributing the particles?
  • How much ventilation is required to make indoor risk more similar to outdoor risk?
  • Do plexiglass or masks actually help much?
  • What level of risk are we aiming for in workspaces and why?
    Medical practice uses the concept of Universal Precaution, but I cannot see that we can all wear PPE