I think the fact that Shakespeare lived in London, which was the densest city of the time and a very successful metropolis — that was not an accident. Cities really are an engine of innovation. They are where so many of our good ideas originate. Ten years ago and people were saying, now that we’ve got Skype, email and video chat cities will wither. Of course that hasn’t happened because cities are more valuable than ever before. Being around all these other smart people makes us smarter.