TOM CLARK
© ERIC PIERMONT/AFP VIA GETTY IMAGES
Can a book change the world? Thomas Piketty looked as startled as anyone when his first doorstopper on inequality was greeted with this question six years ago. I remember the scholarly statistician’s transformation into a media sensation vividly, because the Guardian had me take a taxi with him around London to make a (possibly) comic video billed as “on tour with the rock-star economist.”