When it comes to the spread of COVID-19, some businesses present far larger risks than others, according to new research from Stanford and Northwestern. After combining mobile phone data and infection statistics in U.S. cities between March and May, the researchers found that restaurants, gyms and hotels are primary culprits in the spread of the virus. And because only 10% of locations accounted for 85% of anticipated infections, the research also suggests that broad scale lockdowns may not be necessary to contain the virus’ spread.