The CPF, or consumptionâÂÂpossibility frontier, is the budget constraint where participants in international trade can consume. Under autarky this constraint is identical to the productionâÂÂpossibility frontier.http://ingrimayne.com/econ/ActionsResults/Exchange.htmlhttps://web.archive.org/web/20080915125455/http://www.colorado.edu/Economics/courses/econ2020/section2/section2-main.htmlhttps://www.questia.com/googleScholar.qst;jsessionid=LhyfLn2MjbpzpyGGXNylZJThwr2v08r8FzlywvzLJvsW96yjL7P4!-1569404826?docId=95859775