alt Hacker NewsIt's not that pre-industrial society causes slavery, it's closer to the other way round. If you're pre-industrial then everyone has to do farm work, yes, but slavery is /economically inefficient/ because the slaves don't provide demand (since you don't pay them) and don't grow the economy.
This is why economics was called "the dismal science" - economists told people to stop doing slavery and the slaveowners called them nerds. They wanted to own slaves because they wanted to be mini-tyrants, not because they were good at capitalism. Adam Smith did not go around telling people to own slaves.
Replies
Nope. If the only kilowatts at your disposal are the ones that you, your slaves and your horses can digest, you cannot just upscale the production of goods (or anything else) arbitrarily. The whole economy is bottlenecked on production which is bottlenecked on energy supply. Increasing the demand when supply is the problem would only make things worse.
However once you're burning coal (or harness the wind in case of dutch) things are very different, kilowatts flow freely and all the things you say above start to be true.
You are right that slavery is economically inefficient and that economists were one of the fiercest crusaders against slavery etc.
However: lack of demand is not a problem. People can create any amount of total nominal demand for basically free, as long as you have access to a printing press. (And with some minor caveats that's generally true in a gold standard setting, too.)
And even without that: your argumentation would suggest that as long as the slave-owners lavishly spend the money they save on wages, the economy would do just as well as without slavery. That's not the case; have a look at the arguments of the very economists you mention.