Why would anyone volunteer to pay someone the same for 20 hours of work, that they were previously making working 40 hours
That's kindof my point. The only way to get hours to go up (and/or wages to go down) is to reduce the supply of labor. Currently improving
efficiency is increasing the supply of labor which is why wages are stagnant. If the supply of labor went down (via war, legislating reduced
hours, reducing work visas, etc..) then we would see more competition for workers and therefore higher wages.
At that point in time, the only thing of value will be raw material and truly subjective pleasures like artisanal food/wine, art/music.
Now that would be a shift that would fundamentally break supply/demand.
We're pretty much there in some industries. Injection molding and even things like computer cases after a certain quantity the cost is
almost entirely composed of raw material and transportation costs.