From zero to seventy (billion)

SEVERAL of America’s great industrialists built empires in Pittsburgh, including Andrew Carnegie, a steel magnate. Now the city is attracting the attention of a new, aspiring robber baron. Last year the ride-hailing firm Uber swooped down on a robotics research centre run by Carnegie Mellon University in search of autonomous-vehicle expertise. It has been testing self-driving cars on Pittsburgh’s roads for months, and will soon begin offering customers the chance to request rides in one.