A Literature Review and Meta Analysis of the Effects of Lockdowns on COVID 19 Mortality

crucial which may have affected <strong>the</strong> quality <strong>of</strong> <strong>the</strong> papers. Including <strong>the</strong>m makes it possible to
compare <strong>the</strong> results <strong>of</strong> early studies to studies carried out at a later stage. 20
The role <strong>of</strong> optimal timing
We exclude papers which analyze <strong>the</strong> effect <strong>of</strong> early lockdowns in contrast to later lockdowns.
There’s no doubt that being prepared for a p<strong>and</strong>emic <strong>and</strong> knowing when it arrives at your
doorstep is vital. However, at least two problems arise with respect to evaluating <strong>the</strong> effect <strong>of</strong>
well-timed lockdowns.
First, when COVID-19 hit Europe <strong>and</strong> <strong>the</strong> United States, it was virtually impossible to determine
<strong>the</strong> right timing. The World Health Organization declared <strong>the</strong> outbreak a p<strong>and</strong>emic on March 11,
2020, but at that date, Italy had already registered 13.7 COVID-19 deaths per million. On March
29, 2020, 18 days after <strong>the</strong> WHO declared <strong>the</strong> outbreak a p<strong>and</strong>emic <strong>and</strong> <strong>the</strong> earliest a lockdown
response to <strong>the</strong> WHO’s announcement could potentially have an effect, <strong>the</strong> mortality rate in Italy
was a staggering 178 COVID-19 deaths per million with an additional 13 per million dying each
day. 21
Secondly, it is extremely difficult to differentiate between <strong>the</strong> effect <strong>of</strong> public awareness <strong>and</strong> <strong>the</strong>
effect <strong>of</strong> lockdowns when looking at timing because people <strong>and</strong> politicians are likely to react to
<strong>the</strong> same information. As Figure 4 illustrates, all European countries <strong>and</strong> U.S. states that were hit
hard <strong>and</strong> early by COVID-19 experienced high mortality rates, whereas all countries hit
relatively late experienced low mortality rates. Björk et al. (2021) illustrate <strong>the</strong> difficulties in
analyzing <strong>the</strong> effect <strong>of</strong> timing. They find that a 10-stringency-points-stricter lockdown would
reduce COVID-19 mortality by a total <strong>of</strong> 200 deaths per million 22 if done in week 11, 2020, but
would only have approximately 1/3 <strong>of</strong> <strong>the</strong> effect if implemented one week earlier or later <strong>and</strong> no
effect if implemented three weeks earlier or later. One interpretation <strong>of</strong> this result is that
lockdowns do not work if people ei<strong>the</strong>r find <strong>the</strong>m unnecessary <strong>and</strong> fail to obey <strong>the</strong> m<strong>and</strong>ates or if
people voluntarily lock <strong>the</strong>mselves down. This is <strong>the</strong> argument Allen (2021) uses for <strong>the</strong>
ineffectiveness <strong>of</strong> <strong>the</strong> lockdowns he identifies. If this interpretation is true, what Björk et al.
(2021) find is that information <strong>and</strong> signaling is far more important than <strong>the</strong> strictness <strong>of</strong> <strong>the</strong>
lockdown. There may be o<strong>the</strong>r interpretations, but <strong>the</strong> point is that studies focusing on timing
cannot differentiate between <strong>the</strong>se interpretations. However, if lockdowns have a notable effect,
we should see this effect regardless <strong>of</strong> <strong>the</strong> timing, <strong>and</strong> we should identify this effect more
correctly by excluding studies that exclusively analyze timing.
20
We also intended to exclude studies which were primarily based on data from 2021 (as <strong>the</strong>se studies would be
heavily affected by vaccines) <strong>and</strong> studies that did not cover at least one EU-country, <strong>the</strong> United States, one U.S.
U.S. state or Latin America, <strong>and</strong> where at least one country/state was not an isl<strong>and</strong>. However, we did not find any
such studies.
21
There’s approximately a two-to-four-week gap between infection <strong>and</strong> deaths. See footnote 29.
22
They estimate that 10-point higher stringency will reduce excess mortality by 20 “per week <strong>and</strong> million” in <strong>the</strong> 10
weeks from week 14 to week 23.
11