I agree that cheap labor starves innovation, but the cause of cheap labor is not a lack of a social system that boosts wages. It's lots of competitors trying to

I agree that cheap labor starves innovation, but the cause of cheap labor is not a lack of a social system that boosts wages. It's lots of competitors trying to hire away your employees. The only way this is possible is by making it easier for new firms to enter the market. I'm not sure about Rome specifically, but in general, merchants and other businesses before the 18th century needed social connections and permission from their lords/kings/governors before opening a business. A 'corporation' was originally nothing more than a charter from your government saying you have permission to conduct business.