Since their founding less than a decade ago, Uber and Airbnb have wrangled with regulators, challenged the taxi and hotel industries, earned extraordinary valuations from venture capital investors — and fundamentally transformed the way people think about urban transportation and travel. In his new book, The Upstarts: How Uber, Airbnb, and the Killer Companies of the New Silicon Valley Are Changing the World, veteran Bloomberg technology writer Brad Stone unravels the facts from the mythology surrounding the companies’ rise. He talked with HBR about what makes these generation of tech startups different from the ones that came before. Our conversation has been edited for length and clarity: