I noted recently that the British Government still hasn’t published a cost-benefit analysis of lockdown, more than a year after the first one was implemented. Instead, the task has been left to academics and others working outside of government, who’ve found that the costs almost certainly outweighed the benefits.
Now two economists based in Bolivia have attempted something similar at the global level. What they’ve done isn’t quite a cost-benefit analysis, as I’ll explain, but it puts the vast costs of lockdown into perspective.
Lykke Andersen and Alejandra Rocabado compared changes in the quantity and quality of life during the first year of the pandemic. They focus on a sample of 124 countries, which collectively account for 96% of the world’s official COVID-19 death toll.
To measure the quantity of life lost in 2020, the authors used the total number of excess life-years lost. And to measure the quality of life lost, they used the percentage reduction in the Google mobility index, averaged across different categories (retail, residential, etc.)
To simplify their analysis, the authors assume that “a 100% reduction in mobility for a year is equal to a lost year of life”. In other words, if average mobility fell by 20% in a country, then everyone in that country lost 1/5th of a quality life-year. This is a strong (and arguably unrealistic) assumption, but it’s useful for trying to get an overall sense of what happened.
The authors find that the world lost 48 million life-years due to people dying from COVID-19, but lost 1.25 billion quality life-years due to reductions in mobility. This means that the loss in quality of life was 25 times larger than the loss in quantity. The only three Western countries where the ratio was less than 2 were Denmark, Finland and Sweden.
How big is the 48 million number? As the authors note, “Every year, at least twice as many life years are lost due to children dying of diarrhea.” (Note that a child who dies of diarrhoea loses 50 or 60 life-years, whereas the average victim of COVID-19 loses only 5 or 10.)
One caveat is that data on excess deaths are not available for many developing countries, so in these cases the authors had to use official COVID-19 deaths, which are almost certainly undercounts. On the other hand, they used estimates of the average number of life-years lost per death that look to be on the high side. Overall, the 48 million number probably isn’t too far off the true amount.
Another point worth noting is that one can’t attribute the entirety of the 1.25 billion number to the impact of lockdowns. Some reduction in mobility would have happened anyway, due to voluntary social distancing. But even if it were cut in half, the total loss of quality life-years would still be 12.5 times larger than the loss in quantity.
Whether you buy their conclusions or not, Andersen and Rocabado’s paper is worth reading in full.