Early in the pandemic, a consoling narrative emerged: COVID-19 was largely killing people who would have died soon anyway. The "mortality displacement hypothesis" suggested that excess deaths would be followed by a compensating deficit in deaths—a grim rebalancing as the most vulnerable succumbed earlier than expected.
It was a way of making sense of the numbers. It was also, according to new research published in JAMA Network Open, wrong.
An analysis of mortality data from 34 high-income countries shows a sustained rise in excess deaths years after the pandemic's acute phase, with no evidence of the predicted deficit. The universe doesn't care what we believe. Let's find out what's actually true.
The study examined all-cause mortality from 2020 through 2023 across countries including the United States, United Kingdom, Germany, France, and Australia. If the mortality displacement hypothesis were correct, countries with high excess deaths in 2020 should have seen below-expected deaths in subsequent years.
Instead, excess mortality remained elevated in 2021, 2022, and 2023. Some countries saw their highest excess mortality in years after 2020. This pattern held even after accounting for demographic changes and seasonal variation.
What explains this? Several mechanisms are likely at play. Long COVID may be causing premature deaths from cardiovascular disease, neurological conditions, and immune dysfunction. Healthcare disruptions delayed cancer screenings, routine surgeries, and chronic disease management. Mental health deteriorated, contributing to increased deaths from suicide and substance abuse.
There's also the direct toll of subsequent COVID waves. While vaccines reduced individual risk, repeated waves continued to kill vulnerable populations—and with each infection, more people joined that vulnerable group.
The mortality displacement hypothesis wasn't invented by callous statisticians. It's a real phenomenon observed in heat waves and flu seasons. During the 2003 European heat wave, excess deaths in summer were partially offset by fewer deaths that winter. But COVID-19 doesn't appear to follow that pattern.
This matters for policy. If COVID merely "harvested" the already-dying, the case for aggressive mitigation weakens. But if it created vulnerability and generated sustained mortality, the calculus changes. The pandemic's death toll isn't just the direct COVID deaths—it's the years of elevated mortality that followed.
The research has limitations. It's observational, based on aggregate data. Individual-level mechanisms remain unclear. And 2020-2023 saw multiple confounding factors—opioid epidemics, political instability, healthcare system stress.
But the pattern is clear: COVID-19 did not simply bring forward deaths that would have occurred soon anyway. It appears to have fundamentally increased mortality risk for millions of people, with effects that persist years later.
The universe doesn't care what we believe. But we should care what the data shows.
