As several countries slide back towards the spectre of Covid-21 lockdowns, this is perhaps an opportune moment to consider whether we actually learned anything from Covid-19 and the policy reactions around it. On the face of it, the answer would appear to be a firm “no”, as governments continue to react on the basis of at best short-term considerations and at worst, aesthetics.

Some time ago on another blog (Noah Smith on Substack), whose contents are interesting if rather pre-2016 in their globalism, a piece was posted on why lockdowns were so great. But the real gold here was in the comments, and I unashamedly publish one such comment in its entirety below, which makes the point valid then but even more so now: lockdowns never work because they are always closing the stable door after the horse has bolted. There is no viable way for most countries to get lockdowns right and effective. As a result, it is not very clever to try.

The commenter (presumably an Arsenal suppporter, disappointingly), retorts to Smith’s article thus:

The problem with this article – and with lockdowns in general – is that they assume they can control exponential growth. It’s been pretty well established that in most cases COVID-19 follows a logistic curve (in terms of cumulative cases and deaths). In order to stop a spike in cases and deaths you need to two things to work out for you. Firstly you need to get the timing of the lockdown correct and – more importantly – the lockdown has to take R below one.

There are some very big issues with this approach. One is that all three lockdowns, COVID infections (i.e. day 0 of a covid case) have peaked before lockdown measures took place. Professor Simon Wood of the University of Edinburgh has done some excellent work on this. It appears that we are as good at timing lockdowns as investors are at timing the market.

Secondly and more controversially, lockdowns are not effective in reducing infections. They do not work. If we examine the November lockdown we see that there is only a small decrease in infections after a lockdown is imposed. In the March and January lockdowns, infections were already decreasing in the days before lockdown and the R value was also decreasing prior to lockdown. Lockdowns may increase the rate at which R decreases (dR/dt), but the evidence for this is slim at best. For evidence of all of this, see the two graphs from Simon Wood.

Further evidence for lockdown 3 can be found here. On a more local level, we see such proof for this again and again in the failed local lockdowns in Leicester and the north of England. In London, cases were increasing rapidly in certain boroughs towards the end of the November lockdown. While the B117 variant and schools being open may have been factor in this, it further weakens the case for lockdowns. A collection of 35 papers have also reached similar conclusions. 

Despite all of this evidence against lockdowns, let us assume that they work to some extent. In order to justify them, the government must demonstrate the benefits of the lockdown outweigh the costs. Miles et al examined this and found that the “lowest estimate for lockdown costs incurred was 40% higher than highest benefits from avoiding the worst mortality case scenario at full life expectancy tariff and in more realistic estimations they were over 5 times higher“.

It appears that there are only two viable approaches to fighting COVID-19, the first being the “zero COVID” approach used by Taiwan, South Korea, Australia and New Zealand. The other option is the light touch approach of the US (Texas and Florida in particular) and Sweden. Anything in-between is likely to lead to more job losses and non-COVID excess deaths while doing almost nothing to slow down this disease.

All of these are fully sourced and the sources worth a read. To add to his comments, in retrospect the “zero COVID” approach is also not working, and the examples the author cited at that point have come to be bitten severely with ongoing local lockdowns and major disruptions to life. It seems unlikely that even Australia would continue advocating the “Australia method” these days, and that is before discounting the fact that Australia and New Zealand were able to impose such lockdowns rather uniquely given their island status. A democratic society which is not an island will find these extremely hard to bear.

In reality, even China is now talking about having to come to terms with COVID as something one lives with rather than something one conquers. With the latest Omicron variant demonstrating new levels of mildness in symptoms, we are almost certainly at the point where everyone will have to agree on tolerance towards the virus. Hopefully at least something will have been learned of the last two years, but perhaps this is asking too much.