http://insidescoopsf.sfgate.com/blog...minates-again/

"This year’s survey involved 17,505 diners, which reported above average spending in the Bay Area, with the average $41.87 meal cost for dinner, compared to the national average of $40.53. That said, San Franciscans are still below-average tippers; when a service charge is not automatically included, the average tip in San Francisco is 18.4%, which is below the national average of 19%."

For you trip reporters:

"however, 86% of locals diners say it is... ...“perfectly acceptable” to take photos of your food at the table."