Adam Smith argued that free workers are superior to slaves because they have greater incentive to want to better themselves for their own benefit and to innovat

Adam Smith argued that free workers are superior to slaves because they have greater incentive to want to better themselves for their own benefit and to innovate their processes to show they are worth more wages. Slaves, by contrast, he argues will perform the bare minimum work to avoid repercussions. They are also far from free, they cost money to purchase and there is a cost to providing them with necessities of life as they don't have the means of providing for themselves.