Did San Francisco really lose more residents than any other city last quarter?

Business Insider reported this week that “San Francisco is losing more residents than any other city in the U.S.,” but a closer look at the data reveals this might not be quite true.

Business Insider’s source for that claim is the real estate listing aggregate site Redfin, which released another of its quarterly migration reports this week. Every three months, Redfin analyzes which major U.S. metros it deems likely to lose residents to other cities in the near future.

It’s a telling statistic, but it doesn’t amount to conclusive evidence of population decline. Here are a few takeaways from the latest analysis:

• It’s true that once again San Francisco had the highest “outflow” of any metro area in Redfin’s report. That means that in all, the number of SF residents who used Redfin to search for homes in other metro areas beat the number of people in other cities shopping for SF homes by 15,489. That’s nearly 3,000 more than second-place New York City’s “outflow.”
• However, this doesn’t mean that, as Business Times put it, “San Francisco lost a net 15,489 residents.” Redfin only measures the “portion of local users searching elsewhere.” It seems unlikely every one of those San Franciscans who searched for homes in another city actually bought one and moved—even if they did, there’s no way to measure that migration right now.

Brian Lopez

• Redfin spokesperson Jon Whitely tells Curbed SF, “The migration reports define a migrant as a logged-in Redfin user that has viewed at least ten listings [in another city] during the quarter. We also excluded locations that in aggregate represented less than 20 percent of a user’s searches” to rule out users who just clicked on a few dream homes elsewhere. That kind of consistent pattern probably does indicate serious consideration for moving, but Whitely admits “we can’t tell who actually leaves.”
• The fact that San Franciscans use Redfin more than home shoppers in some other cities distorts the data a bit. A much higher percentage of New Yorkers—a third in all—used the site to look for a home in another city, but that third only added up to an outflow of 12,532 people on account of a smaller sample size to begin with.
• SF’s 19.4 percent rating of outbound searches on Redfin is 1.2 points higher than the site reported in November, but about the same as in April of last year. The 15,489 figure is down from nearly 16,000 in November as well.
• Redfin blogger Greg McCarriston writes that the general trend in the data is that “affordable inland metros” are attracting coastal dwellers, which in the case of San Francisco was somewhat true. San Franciscans searched most often for homes in Sacramento. But the most popular out-of-state browsing option was Seattle, Washington.
• According to the U.S. Census, San Francisco’s population is increasing consistently every year. However, the most recent estimate (released last September) showed an annual gain of almost exactly 6,000 people in 2016, much less than the 11,000-13,000 gains seen in recent years. This might be the beginning of a tapering off in migration—or it might just be a one-year fluke. The numbers aren’t in yet.

• SF Residents Moving Away [Business Insider]
• Q4 Migration Report [Redfin]
• SF Losing Home Shoppers [Curbed SF]
• Census: SF Wealthier Than Ever [Curbed SF]