In our free-for-all information ecosystem, the liars have the inside track. It’s much easier to make up outrageous claims about, say, migrants than it is to send reporters into the field and check facts. The more outrage a bogus claim generates and the more often it’s repeated, the more widely it spreads. That’s human nature. So it’s encouraging to encounter a model that tilts back in favor of truth. Today’s guest Peter Pomerantsev has identified one such model from history in his book...