The Columbia University sociologist Sudhir Venkatesh studies exclusive worlds by embedding himself — with a crack-selling gang, sex workers, the teenage children of billionaires, and most recently, at the highest levels of companies at the vanguard of the digital revolution, including Facebook and Twitter. And now he’s hosting a podcast. In each episode, Venkatesh will reveal what he learned in Silicon Valley and talk with the people he met along the way who are building and running the digital world, and those who are using it in a signal way, digging deep into their motivations and...