These San Francisco neighborhoods noticed greatest exodus throughout pandemic

San Franciscans fled the city last year. Previous reports have shown that many of them have left for more spacious homes in more affordable regions. Our analysis found that they have left even the densest parts of the city in droves, eroding downtown and other once-bustling neighborhoods.

The Chronicle received data from the U.S. Postal Service about households in San Francisco that changed their address during the first nine months of the pandemic. The data shows that from March to November 2020, in most postcodes, the number of residents who left the country increased dramatically compared to the same period in 2019. USPS has not provided batches of address changes from one zip code to another totaling 10 or less, citing privacy concerns. This means that the data will likely not include all of the address change requests made by those zip codes, but it will still capture the majority of the requests made.

Only two postcodes – 94129, which includes the Presidio, and 94124 at Bayview Hunters Point – had fewer extracts in the first part of the pandemic than in the same period in 2019. The Presidio’s postcode saw a 72% postcode decrease who move out, while Bayview’s zip code saw 47% fewer moves. These two postcodes are among the five least densely populated in the city.

At the other end of the spectrum, 94108 – the densest zip code in San Francisco with more than 52,000 people per mile – saw a nearly 620% increase in excerpts. The zip code 94108 includes parts of downtown, Chinatown, and Nob Hill. Right next door, 94104, a zip code that spans a tiny part of the financial district, the move out rose more than ten times, or over 1,000%. The 94104 zip code is not one of the densest zip codes for the resident population, but it is in a busy part of downtown.

Additionally, zip code 94123, which represents the Marina and Cow Hollow, had about 150% more excerpts from March to November 2020 than the same period last year, as did zip code 94122 inside Sunset. Both postcodes are above the median density of the city.

Overall, our analysis shows a strong association between population density and increased exodus during the pandemic. Using U.S. census data, we recorded the relationship between the density of each zip code and how the statements changed during the first nine months of the pandemic. We excluded postcodes with fewer than 100 extracts in 2019.

Roughly speaking, for every 10,000 people per mile increase in population density, the excerpt change in a zip code was 25 percentage points greater.

While downtown San Francisco small business owners are hoping many office workers will return to the city soon, a significant portion of these moves could be permanent. Big downtown tech companies like Google and Facebook have announced they will allow more flexible hours after the pandemic, while some companies like Twitter are trying to give up office space in San Francisco indefinitely.

Even if many San Franciscans fled downtown, most didn’t go far: Research by the California Policy Lab found that most Bay Area residents who moved in their first three years stayed San Francisco at higher rates during the pandemic Leaving rates have shifted quarters of 2020 to other parts of the state.

Susie Neilson is a contributor to the San Francisco Chronicle. Email: susan.neilson@sfchronicle.com Twitter: @susieneilson