Earlier quoted context omitted.
I think the point he was trying to make still holds without such absurd multipliers as "doubling", it's just an intuitively easy to grasp multiplier. What he's saying is that increasing your number of hours may get more absolute work done, but proportionally a person accomplishes less as more hours are worked. Thus, the correlation between time in office (hours) and productivity (work accomplished per unit time) is a…
You are implying that childcare and other non-work flex time activity isn't work. This is, in the frame of this discussion, in itself implicitly sexist. Women aren't asking for flex time in order to relax: they want flex time in order to do work that isn't business related, like taking care of their family. So the same number of hours are being worked - the question is whether using these extra hours to do company bu…
I doubt anyone is implying that. Clearly "productivity" in this context specifically referring to the firm that is employing the individual.