The biggest problem with collaboration is that it makes what Mr Newport calls “deep work” difficult, if not impossible. Deep work is the killer app of the knowledge economy: it is only by concentrating intensely that you can master a difficult discipline or solve a demanding problem. Many of the most productive knowledge workers go out of their way to avoid meetings and unplug electronic distractions. Peter Drucker, a management thinker, argued that you can do real work or go to meetings but you cannot do both. Rest