Why does Faxian describe the inhabitants of pataliputra rich and prosperous?

i believe it would be capitalism

most people now work in jobs where they do one  kind  of work; they are carpenters, bankers, cooks, mechanics, and so forth. likewise, most  businesses produce  only certainkinds  of  goods  or  services, such as cars, tacos, or gardening  services. this feature of  production  is known as specialization.

b europeans take corn to africa. corn becomes an important crop there.