Agreed! Alexis de Tocqueville had similar arguments about slavery and it's economic inefficiencies. Sadly part of his argument was not based on civil liberties and rights rather his argument was the expense of the "up keep", housing and feeding slaves, versus an individual worker who is free has to provide their own cost of living for which that burden is then lifted off the master/owner. The business owner simply pays the worker for his/her labor, and no more feeding and housing. It saves expenditure burden on the owner and transfers the cost to the worker, maximize profits.

Wonder what he would say to the mechanization of labor through technology and its benefits of ending the institution of slavery and providing owners cheaper or eliminating labor expenditure?

So just another view point on the issue of "inefficiency of slavery" argument.