Cellphone data suggests Bay Area not as compliant with new shutdown as it was in the spring

Some have questioned whether the new stay-at-home order currently in effect in the Bay Area would be followed as closely as the one in effect in the spring, and new cellphone data would support the theory compliance is not as high now as it was at the start of the pandemic in March.

The data company Unacast, a firm that collects cellphone location data from millions of phones for private companies, created the "Social Distancing Scoreboard" that shows which counties in California and beyond are seeing compliance in getting people to stay home. Each county and state is graded on an A through F scale based on three criteria: change in average mobility based on distance traveled, change in nonessential visits and difference in encounter density.

In the spring, the firm used only change in average mobility when compared to normal times to calculate grades, but has since added the other two criteria.

"Travel distance is one aspect, but of course people can travel far without meeting a soul or travel 50 feet and end up in a crowd — so we know that the real world picture can be quite complex," Unacast writes in its methodology. "As noted above, changing behavior will trigger adjustments in our data strategy. That's why, post launch, we will be continuously working to improve our social distancing models."

On March 30 — two weeks after six Bay Area counties issued a stay-at-home order and one week after it was adopted statewide...