Rothbard gives the 7% figure on p. 6 of “Economic Thought before Adam Smith.” He doesn’t provide a citation, so I’m not sure where he got that number, but it doesn’t seem unreasonable. When I get back to the office Monday, I’ll check a source or two and see if I come up with anything different. The figure will naturally fluctuate depending on what moment in Athenian history you’re examining.
