Jonas Herby, Lars Jonung and Steve H. Hanke, “A Literature Review and Meta-Analysis of the Effects of Lockdowns on COVID-19 Mortality”, Studies in Applied Economics, Johns Hopkins (SAE, #200, January 2022)

In this literature review and meta-analysis, researchers publishing in Johns Hopkins University's Studies in Applied Economics find that lockdown measures put in place during the early stage of the pandemic in Europe and the US reduced COVID-19 mortality by a mere 0.2%. They conclude:

"While this meta-analysis concludes that lockdowns have had little to no public health effects, they have imposed enormous economic and social costs where they have been adopted. In consequence, lockdown policies are ill-founded and should be rejected as a pandemic policy instrument." (emphasis added)

Update: By way of balance, I note that this study had been criticised by the "fact-checking" organisation Health Feedback, here. (I also note that this organisation receives part of its funding from Facebook and Google, here.)