Tests Versus Lockdowns

Mass testing policies do less damage to the economy.

Implementing a mass testing policy is the safest way to reopen society and has much less of a damaging impact on the economy than a hard lockdown, according to new research. Abderrahim Taamouti, professor of economics and finance Durham University Business School in the United Kingdom, has developed an epidemic model to study how infection control is impacted by the two related factors of lockdown and testing.

His results show that when a country imposes a soft lockdown—that is, about a 10 percent shutdown of economic activity—then officials need to test about 4 percent of the population each day to control COVID-19 infection. However, when a country imposes a 30 percent shutdown of economic activity, it only needs to test about 1.5 percent of the population daily to get the infection under control. 

Taamouti also studied a model with a time-varying testing policy that mimics the dynamic of infection, accounting for expansion, peak, and decline phases. This model shows that, for a three-month time period, infection will be under control when the maximum daily testing capacity reaches 7 percent of the population—even when the test used is not highly reliable. However, when maximum daily testing capacities are as low as 0.1 percent, the infection will only be controlled if there is a lockdown of at least 65 percent.

“Hard lockdowns are likely to cause the worst recession in a century,” says Taamouti, “and most countries have only been testing on a small scale.” He notes that countries such as Iceland, Germany, and South Korea—which tested greater proportions of their population than the rest of the world—fought the pandemic well by quickly isolating or treating COVID-19 patients. He adds, “These countries that managed to keep their case counts and deaths tolls low have also reopened their economies earlier than most other countries.”

Taamouti offers the example of the U.S., where it’s estimated that the cost of COVID-19 lockdown is between US$4.2 trillion and $5.4 trillion a year, whereas the cost of a testing 7 percent of Americans daily would cost an estimated US$550.55 billion a year.