A new study from Johns Hopkins University’s Institute for Applied Economics supports what I and others have long maintained: lockdowns do not work, and their economic, social, educational, and psychological costs far outweigh any health benefits they might bring.
Early in the pandemic, epidemiological modelers predicted catastrophic casualties that could be averted only with stringent lockdown measures. In response, nearly every country around the world imposed lockdown measures by the end of March 2020. Yet little evidence existed to support such actions, and the modeling studies were fatally flawed. Now the Hopkins literature review and meta-analysis, by Professors Jonas Herby, Lars Jonung, and Steve Hanke, finds that lockdowns—“defined as the imposition of at least one compulsory, non-pharmaceutical intervention (NPI)” such as school and business closures and limitations on movement and travel—“had little to no effect on Covid-19 mortality.”
The authors reviewed thousands of studies and culled 34 that had reliable and sufficiently relevant data to review. The results were mixed: several studies found no statistically significant effect of lockdowns on mortality; other studies found a significant negative relationship between lockdowns and mortality; and others found a significant positive relationship between lockdowns and mortality—i.e., that lockdowns actually increased deaths from Covid-19.
When the authors performed a meta-analysis—a statistical technique that combines the results of multiple studies addressing the same question and uses the pooled data to draw conclusions—they found that lockdowns failed to show a large significant effect on Covid-19 mortality: “the effect is little to none.”
The Hopkins findings echo and confirm the conclusions in an April 2021 review by Canadian economist Douglas Allen that lockdowns had little or no impact on the number of Covid-19 deaths. Allen’s review of studies that distinguished between voluntary and mandated lockdown effects found that voluntary changes in behavior explained most of the changes in cases and deaths. In a January 2021 review, Danish economist Jonas Herby, a coauthor of the Hopkins study, found that voluntary behavioral changes were ten times as important as mandatory measures in limiting the growth of the pandemic.
More than 20 years ago, economist Tomas Philipson described how individuals change their behavior in response to infectious-disease outbreaks: they voluntarily act to avoid health risks and costs and they also respond to public-health mandates such as lockdowns taken to control the spread of disease. During the Covid-19 pandemic, individuals, hospitals, and other businesses all acted before government mandates to limit disease spread.
Moreover, as economists would predict, individuals’ actions and compliance with government measures responded to the degree of perceived risk at the moment. As Covid-19 prevalence rose, people stayed home and avoided large groups and indoor activities. As prevalence fell, people resumed normal activities. Even if lockdown measures are effective in the short run, changes in risky voluntary behaviors and compliance with public-health measures in response to that success may counteract the lockdowns’ benefits.
Most of the epidemiological models relied on by policymakers during the pandemic—particularly the highly influential Imperial College of London model—did not account for these voluntary effects. One widely cited Imperial College paper from June 2020 that attributed decreased European Covid-19 deaths entirely to lockdowns acknowledged as much. “We do not account for changes in behavior,” the researchers wrote—changes, they conceded, that would lower deaths “even in the absence of government interventions.”
The Hopkins researchers also speculated that the lockdown measures may have worsened the pandemic by forcing people to shelter in their homes where they were more likely to become infected or infect family members than if they had been allowed access to safer places like outdoor venues or workplaces that were instituting safety protocols. This is consistent with work from University of Chicago economist Casey Mulligan, who found that private companies voluntarily implemented infection-prevention measures that lowered workplace Covid-19 transmission to levels below household rates.
While lockdowns had little to no public health benefits, they imposed enormous economic and social costs. Job losses in March and April 2020 exceeded 22 million and have not yet been fully recovered. Children lost years of educational and social development that will affect them for the rest of their lives. Psychological problems have soared throughout society. It’s hard to disagree with the Hopkins’ researchers’ conclusion that lockdowns “should be rejected as a pandemic policy instrument.”
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