New study finds lockdowns may have actually increased deaths
Do lockdowns save lives? An important new paper from the prestigious National Bureau of Economic Research (NBER) in the US examines the impact of “shelter-in-place” (SIP) policies on excess mortality across a sample of 43 countries and all US states. Focusing on excess mortality is important as it gets around problems of measuring deaths from COVID-19 and will also include deaths caused by lockdowns.
The authors conclude:
“we fail to find that SIP policies saved lives. To the contrary, we find a positive association between SIP policies and excess deaths”.
A key issue with this type of analysis is endogeneity, i.e. it is possible that lockdowns are introduced partly because deaths are already rising. As a result, you may observe a spurious positive correlation between lockdowns and mortality. The authors control for this and find the opposite: “countries that implemented SIP experienced a decline in excess mortality prior to implementation compared to countries that did not.”
The authors are open to different explanations of the result. For example, it may be that lockdowns have essentially no direct causal impact even on Covid-deaths. Alternatively, lockdowns may reduce Covid-related deaths somewhat but this reduction is outweighed by increases in other deaths caused by the lockdown.
Note that even if lockdowns did reduce mortality, the impact would have to be very large to justify the huge societal costs imposed (in terms of harms to the economy, public health, education and other aspects of civil life). That lockdowns do not even seem to reduce mortality is devastating to the pro-lockdown case.