A little while ago, I had a chance to visit New York’s City Hall, where Michael Bloomberg – the former trader-turned-financial-information-mogul – now works as mayor. As I entered his empire, I experienced a small shock.

During my career as a journalist, I have often walked through government buildings, and become accustomed to seeing a rabbit warren. Across the western world, senior officials typically work from offices interconnected by corridors, guarded by secretaries in ante-chambers.

Bloomberg’s building in downtown Manhattan, though, is different. He sits in a vast, airy, open-plan room, surrounded by officials and banks of giant data screens (showing information on things such as traffic flows or public satisfaction with the police). Anybody holding a meeting is encouraged to sit on a central, raised dais, rather than scuttle into a private hole; the idea, as one employee explained, is to encourage a climate of transparency and collaboration. In theory, in other words, anyone in the mayor’s office can see – and yell at – everyone else; much as they can on a modern financial trading floor or at a newspaper (which, of course, is no accident given that Bloomberg spent most of his career building the financial information giant that bears his name).