A new study, published as a working paper for the leading U.S. think tank National Bureau of Economic Research (NBER), has shown (once again) that lockdown policies produced no discernible reduction of the pandemic death toll. If anything, they increased it.
The study uses excess deaths rather than Covid deaths to avoid the problems of different ways of counting Covid deaths, and also to capture policy deaths from lockdowns and other Government responses. It looks at the death tolls in 43 countries and all U.S. states to see how they varied with the length and timeliness of lockdown “shelter-in-place” (SIP) orders.
The authors find that longer lockdowns led to more excess deaths: “Countries with a longer duration of SIP [shelter in place] policies are the ones with higher excess deaths per 100,000 residents.” For U.S. states the finding was similar but less pronounced.
In U.S. states, earlier lockdowns were associated with slightly higher excess deaths rather than lower as lockdown theory would predict. In the comparison of countries, on the other hand, the predicted relationship was found.
To account for differences between countries and states (such as demographics) the authors carried out “event studies” to see how much each country or state’s excess deaths changed following lockdown from its pre-lockdown trend. This analysis showed that, prior to implementing lockdown policies, the trend of lockdown countries was towards having lower excess deaths than countries that didn’t implement lockdowns. However, after lockdown those trends were reversed so that lockdown countries started to have progressively worse excess deaths compared to no-lockdown countries.
The results from the event study regression models suggest that difference in excess mortality between countries that implemented SIP versus countries that did not implement SIP was trending downwards in the weeks prior to SIP implementation. Had this pre-existing difference in mortality trends continued, we would expect lower excess mortality in the weeks following SIP implementation in countries that implemented SIP policies relative to countries that did not implement policies. However, we find that the pre-existing trend reversed following implementation of SIP policies. This suggest that our estimates of the effects of SIP on excess mortality are conservative as pre-existing trends are biased towards finding a protective effect of SIP.
The authors conclude that “the implementation of SIP [lockdown] policies does not appear to have met the aim of reducing excess mortality”.
They offer some reasons for why this might be the case.
There are several potential explanations for this finding. First, it is possible that SIP policies do not slow COVID-19 transmission. As discussed earlier, prior studies find only a modest effect of SIP policies on mobility. A potential reason for the modest impact on mobility may be that individuals change behaviour to avoid COVID-19 risk even in the absence of SIP policies. It is also unclear whether modest reductions in mobility could slow the spread of an airborne pathogen.
Second, it is possible that SIP policies increased deaths of despair due to economic and social isolation effects of SIP policies. Recent estimates in the U.S between March and August 2020 show that drug overdoses, homicides, and unintentional injuries increased in 2020, while suicides declined.
Third, existing studies suggest that SIP policies led to a reduction in non-COVID-19 health care, which might have contributed to an increase in non-COVID-19 deaths. For example, one study in the United Kingdom predicts that there will be approximately an additional 3,000 deaths within five years due to a delay in diagnostics because of the COVID-19 pandemic.
In light of this evidence, continued reliance on SIP policies to slow COVID-19 transmission may not be optimal. Instead, the best policy response may be pharmaceutical interventions in the form of vaccinations and therapeutics when they become available. Early evidence suggests that initial vaccination efforts have led to large reductions in COVID-19 incidence. Policy efforts to promote vaccination are thus likely to have large positive impacts.
The study adds to the ever-growing collection which show that lockdowns are not just extremely costly, so unlikely to be worth the price tag, but perhaps most damningly fail to achieve their primary goal of reducing deaths.
Read the full study here.