Actually, there is some evidence that slavery was very economically efficient. 'The Half Has Never Been Told' by E Baptist lays out how enslaved labour picked much more cotton than the then free labour.
That was then, though. Now, when skilled labor is of greater importance and unskilled labor of comparatively little value, I submit that things may well be very different.
That was then, though. Now, when skilled labor is of greater importance and unskilled labor of comparatively little value, I submit that things may well be very different.