San Francisco, California, remains the slowest among 63 major U.S. cities in recovering from the coronavirus pandemic, according to mobile phone data. The new data from the University of Toronto’s School of Cities repeats a finding from early 2023, when San Francisco was last among 62 cities. The recovery index is “computed by counting the number of unique mobile phones in a city’s downtown area in the specified time period, and then dividing it by the number of unique visitors during the equivalent time period in 2019. For example, the March 2023 – May 2023 time period is compared to...