The key question is something like "am I getting the best deal on offer?" for workers and "are these workers having the biggest impact possible?" for managers.

The key question is something like "am I getting the best deal on offer?" for workers and "are these workers having the biggest impact possible?" for managers. The economy provides structures for the two parties to negotiate the best answers they can find. Slavery puts the decisions to the slave owners, economic slavery retains the decision with the worker. If workers are in a terrible situation then at least they can reorganise if they see a better. With slaves they probably could think of better ways to organise, but the owners blocked them from acting. In practice it means workers have and can act on strong incentives to upskill and find more effective working habits.