>Describing Rome as "capitalist" in the modern sense is a gross misrepresentation of what is known about the ancient economy, ignoring the work of Finley and Polanyi.

Government took only 5%.

https://en.wikipedia.org/wiki/Roman_economy#GDP_and_income_d... In the Scheidel–Friesen economic model, the total annual income generated by the Empire is placed at nearly 20 billion HS, with about 5 percent extracted by central and local government.

What does the marginal tax rate have to do with it? The economic structure was not similar to modern industrial organisation.

I don't understand how that's relevant. The citizens of Rome were able to keep 95% of the results of their labor. I'm certainly open to any suggestions you have about reducing my marginal tax rate to 5% if you think Rome is a good example of bringing people out of grinding poverty.

"Citizens of Rome" meaning what? As the traditional meaning is literally the residents of Rome until 90 BCE, then reluctantly Italians. Provincials weren't citizens until 212 AD, and that still left out slaves.