There is no evidence yet that the wave of Black Lives Matter protests across the U.S. sparked COVID-19 outbreaks in the more than three weeks since they began, according to a study published Wednesday by the National Bureau of Economic Research. Rather, as the protests went on, people who were not participating increasingly stayed at home, possibly counteracting any effects the large gatherings may have had on the spread of the virus, the researchers concluded. The paper, which was posted online and is not yet peer-reviewed, looked at data from 315 cities across the country.