Maria Polyakova, an economist at Stanford University, has researched the impact of the pandemic on the US economy. “In general,” she said, “we expect staying at home to mechanically slow the pandemic by reducing the number of interactions between people.”

Updated

Jan. 23, 2021, 11:16 p.m. ET

“The downside is that the reduction in economic activity hurts many workers and their families in particular in the large service sector of the economy,” she added. Is the curfew worth the price?

She is at a loss to understand the logic. “Assuming nightclubs and the like are already closed anyway, prohibiting people from walking around the block with their families at night is unlikely to reduce interactions,” said Dr. Polyakova.

In addition, the virus thrives indoors, and clusters of infections are common in families and households. So a daunting question is whether forcing lengthy tampering with these settings will slow down or speed up the transmission.

“You can think of it that way,” said William Hanage, an epidemiologist at Harvard TH Chan School of Public Health. “What percentage of the transmission events occur in the time in question?” And how will the curfew stop them? “

A study recently published in Science analyzed data from the Chinese province of Hunan at the beginning of the outbreak. Curfews and lockdown measures, the researchers say, had a paradoxical effect: These restrictions reduced the spread within the community but increased the risk of infection in households, reported Kaiyuan Sun, a postdoctoral fellow at the National Institutes of Health, and his colleagues.

Dr. Longini and his colleagues have included bans and curfews in models of the pandemic in the United States and have concluded that they can be an effective way of reducing transmission.