A new study that examined “excess death” data to gauge the impact of shelter-in-place policies on mortality concluded that lockdowns or stay-at-home policies failed to save lives.
Economists from the University of Southern California and the RAND Corporation sought to evaluate the net impact of shelter-in-place (SIP) mandates by examining excess death data from 43 countries and all 50 U.S. states.
Researchers determine excess deaths, or excess mortality, by comparing the observed number of deaths to an expected number of deaths derived from statistical models.
“We use an event study framework to quantify changes in the number of excess deaths after the implementation of a SIP policy. We find that following the implementation of SIP policies, excess mortality increases,” the researchers wrote in a working paper published under the auspices of the National Bureau of Economic Research (NBER).
Looking at data from both the United States and other countries, the researchers concluded, “we fail to find that SIP policies saved lives. To the contrary, we find a positive association between SIP policies and excess deaths.”
“We failed to find that countries or U.S. states that implemented SIP policies earlier, and in which SIP policies had longer to operate, had lower excess deaths than countries/U.S. states that were slower to implement SIP policies,” the researchers wrote.
“We also failed to observe differences in excess death trends before and after the implementation of SIP policies based on pre-SIP COVID-19 death rates,” they added.
While the researchers acknowledged that preliminary evidence suggested that shelter-in-place policies slowed COVID-19 transmission early in the pandemic in the United States, they noted that more recent studies suggest that people changed their behavior—such as wearing masks or social distancing—based on the dynamics of the outbreak, not policies.
Recent studies suggest “individuals changed behavior in response to the severity of the pandemic and the enactment of SIP policy implementation lagged this individual behavior change,” the researchers wrote, concluding that is unclear how much change in COVID-19 risk mitigation is thanks to formal SIP policies compared to health safety measures people would have taken of their own accord.
But even if SIP policies did reduce transmission, the researchers said that their impact on overall health is unclear, as such policies have likely had important unintended consequences like unemployment and increased stress, “potentially leading to increased substance use and suicides.”
“These complex effects suggest that SIP policies might reduce COVID-19 related mortality, but might also increase mortality from other causes,” they wrote.
To support this view, they cited studies suggesting that SIP policies led to a reduction in non-COVID-19 health care, and pointed to recent estimates showing that, in the United States, between March and August 2020, drug overdoses, homicides, and unintentional injuries increased, although suicides declined.
They concluded that relying on SIP policies to slow COVID-19 transmission “may not be optimal” and that, instead, the best policy responses may be pharmaceutical interventions, like therapeutics and vaccines.