The promise that AI will transform the workweek into a three- or four-day week is based on a sound premise, but it ignores the mechanism by which productivity gains are distributed throughout the economy. AI can reduce the time required to complete certain tasks. But there is no guarantee that the time saved will end up on employees’ calendars in the form of a day off. Jamie Dimon, the CEO of JPMorgan, has predicted that AI could lead to a four-…