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

were issued 7½ days after both schools <strong>and</strong> workplaces closed, <strong>and</strong> 12 days after <strong>the</strong> first <strong>of</strong> <strong>the</strong>
two closed. Only one state, Tennessee, issued a SIPO before schools <strong>and</strong> workplaces closed. The
10 states that did not issue SIPOs all closed schools. Moreover, <strong>of</strong> those 10 states, three closed
some non-essential businesses, while <strong>the</strong> remaining 7 closed all non-essential businesses.
Because <strong>of</strong> this, we perceive estimates for SIPOs based on U.S.-data as <strong>the</strong> marginal effect <strong>of</strong>
SIPOs on top <strong>of</strong> o<strong>the</strong>r restrictions, although we acknowledge that <strong>the</strong> estimates may capture <strong>the</strong>
effects <strong>of</strong> o<strong>the</strong>r NPI measures as well.
The results <strong>of</strong> eligible studies based on SIPOs are presented in Table 5. The table demonstrates
that <strong>the</strong> studies generally find that SIPOs have reduced COVID-19 mortality by 2.9% (on a
precision-weighted average). There is an apparent difference between studies in which a SIPO is
one <strong>of</strong> multiple NPIs, <strong>and</strong> studies in which a SIPO is <strong>the</strong> only examined intervention. The former
group generally finds that SIPOs increase COVID-19 mortality marginally, whereas <strong>the</strong> latter
finds that SIPOs decrease COVID-19 mortality. As we will see below, this difference could be
explained by differences in <strong>the</strong> quality dimensions, <strong>and</strong> especially <strong>the</strong> time period covered by
each study.
Table 5: Overview <strong>of</strong> estimates from studies based on SIPOs
Values show effect on COVID-19 mortality
33
Estimate
(Estimated Averted Deaths /
Total Deaths)
St<strong>and</strong>ard
error
Studies where SIPO is one <strong>of</strong> several examined interventions <strong>and</strong> not (as) likely to capture <strong>the</strong> effect <strong>of</strong> o<strong>the</strong>r interventions
Weight (1/SE)
Chernozhukov et al. (2021) -17.7% 14.3% 7 4
Chaudhry et al. (2020) * 0.0% n/a n/a 2
Aparicio <strong>and</strong> Grossbard (2021) 2.6% 2.8% 35 4
Stokes et al. (2020) 0.8% 11.1% 9 3
Spiegel <strong>and</strong> Tookes (2021) 13.1% 6.6% 15 3
Bonardi et al. (2020) 0.0% n/a n/a 1
Guo et al. (2021) 4.6% 14.8% 4 3
Average (median) where SIPO is one <strong>of</strong> several variables 2.8% (0.5%/0.8%)
Studies where SIPO is <strong>the</strong> only examined intervention <strong>and</strong> may capture <strong>the</strong> effect <strong>of</strong> o<strong>the</strong>r interventions
Sears et al. (2020) -32.2% 17.6% 6 2
Alderman <strong>and</strong> Harjoto (2020) -1.0% 0.6% 169 4
Berry et al. (2020) 1.1% n/a n/a 2
Fowler et al. (2021) -35.0% 7.0% 14 2
Gibson (2020) -6.0% 24.3% 4 4
Dave et al. (2020) -40.8% 36.1% 3 3
Average (median) where SIPO is <strong>the</strong> only variable -5.1% (-19.0%/-19.1%)
Precision-weighted average (arithmetic average / median) for all
-2.9% (-8.5%/0.0%)
studies
Note: * Chaudhry et al. (2020) does not provide an estimate but states that SIPO is insignificant. We use 0% when calculating <strong>the</strong>
arithmetic average <strong>and</strong> median. Chaudhry et al. (2020) <strong>and</strong> Berry et al. (2021) do not affect <strong>the</strong> precision-weighted average, as
we do not know <strong>the</strong> st<strong>and</strong>ard errors.
Table 6 presents <strong>the</strong> results differentiated by quality dimensions. Four studies (Chernozhukov et
al. (2021), Aparicio <strong>and</strong> Grossbard (2021), Alderman <strong>and</strong> Harjoto (2020) <strong>and</strong> Gibson (2020))
Quality
dimensions