If you plan to fly during the pandemic, you’re better off choosing an airline with a policy of keeping the middle seat empty. Such a policy lowers the risk of contracting COVID from 1 in 4,400 to 1 in 7,300, according to a new academic study.
That estimate comes from Arnold Barnett, a statistics professor at the MIT Sloan School of Management. His findings—which suggest a “no middle seats” flight reduces risk by 79%—also note that the risk of dying from catching COVID on a flight are less than 1 in half a million.
Barnett’s conclusion on the risk of middle seats comes as U.S. airlines pursue different approaches. For instance, Delta, JetBlue and Southwest have chosen to keep middle seats empty, while United and Spirit are filling them. American is also doing so as it runs many flights that are over-capacity.
The new research should be taken with a grain of salt, however, as Barnett himself acknowledges. In his paper, he emphasizes that his findings are “rough conjecture” in light of the difficulties in calculating such a risk.
Barnett’s calculations are based on numerous assumptions, including that all passengers are wearing masks—a step he says reduces risks of catching COVID by 82%. He also assumes that someone is more likely to catch COVID from those in the same aisle rather than from those in rows behind or in front of them
The findings also disregard the risk of catching COVID from trips to the restroom, or from boarding or getting off the plane. But the latter situation may pose a significant risk according to the Wall Street Journal, which notes the close proximity of passengers waiting to board or scrambling to store luggage.
The Journal, which cited the Barnett study, suggested that flying is not especially dangerous overall, in part because planes frequently replace the air in the cabin.
For his part, Barnett concludes by noting that middle seat policy will also be informed by economic considerations facing the airlines.
“The calculations here, however rudimentary, do suggest a measurable reduction in Covid-19 risk when middle seats on aircraft are deliberately kept open,” he writes. “The question is whether relinquishing 1/3 of seating capacity is too high a price to pay for the added precaution.”
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This story was originally featured on Fortune.com