Because it requires the literal use of government force to suppress market forces, ie to prevent the slaves from refusing to work and running away to find better opportunities.
That doesn't work. You're effectively saying that if I create an army and simply steal from you, that is capitalism because its my own private army. It violates many tenets of capitalism. Buyers and sellers must act voluntarily and enslavement against the will of the slaves, certainly seems to violate this.
That said, even if you simply view the slaves as property with no agency of their own, my original point was more that you can't compare the net worth of the slaves against the slave owners in terms of value created.
>Buyers and sellers must act voluntarily and enslavement against the will of the slaves, certainly seems to violate this.
Can you go into this a bit. In general sellers can acquire materials (oil say) by invading a country and mining it. If that seller then sells the oil acquired thus, I can't see how the buyers and sellers are not acting voluntarily? Is war/violence antithetical to Capitalism in some way that I'm not aware of?
Do you have examples of widespread slave economy that did not require a government framework to support it? All examples from modern civilization i can think of involved laws specifically blocking slaves from participating as equals in the market economy, ie anti capitalist?