For the most part, "Thank You for Being Late" is a master class in explaining. It canters along at a pace that is quick enough to permit learning without getting bogged down. Inevitably he sometimes gets the balance wrong, either allowing his informants to ramble on, or skating over a thorny detail: For instance, having admitted that productivity numbers have not leapt forward in the same way that technology has, he asks us, in effect, to trust him, they will.