The specter of automation hovers over economic prognoses, whether as dream or as nightmare. How much of a threat is automation to jobs? A big one, according to a new report from McKinsey. Although few occupations will be eliminated altogether, most jobs, whether unskilled or high-skilled, include some tasks ripe for automation. Indeed, about half of all activities people are paid to do could be candidates for displacement based on current technologies, amounting to almost $15 trillion in lost wages worldwide, including $2.7 trillion in the US. This may itself be inevitable, but the impact on lives can range from liberating to decimating, depending on whether or not the benefits of automating away socially necessary labor time are shared. Indeed, the coming automation revolution can deliver at last the promise of a post-scarcity economy, providing the greater leisure envisioned by Karl Marx and John Keynes. Or it can lead to a society rife with unrest, divided between the elite few who control the machines and the impoverished many who tend them. A Great Transition or a Fortress World: the choice is ours.