The English noun "commonwealth" in the sense meaning "public welfare; general good or advantage" dates from the 15th century.[1] The original phrase "the common-wealth" or "the common wealth" (echoed in the modern synonym "public wealth") comes from the old meaning of "wealth," which is "well-being." The term literally meant "common well-being." In the 17th century the definition of "commonwealth" expanded from its original sense of "public welfare" or "commonwealth" to mean "a state in which the supreme power is vested in the people; a republic or democratic state."
http://en.wikipedia.org/wiki/CommonwealthHowever, the term "common prosperity" has been often cited in newspapers such as the People's Daily.