Allison Arieff of The New York Times writes:
Tech companies are scrambling to move into cities — there are rumors that Google is going to move here, to San Francisco, from Mountain View. VISA and Akamai have ditched the suburbs to come here. Tech tenants now fill 22 percent of all occupied office space in San Francisco — and represented a whopping 61 percent of all office leasing in the city last year. But they might as well have stayed in their suburban corporate settings for all the interacting they do with the outside world. The oft-referred-to “serendipitous encounters” that supposedly drive the engine of innovation tend to happen only with others who work for the same company. Which is weird.