The GDPs of all nations around the world are from Summers, Robert and Heston, Alan, “A completely new Set of International Comparisons of Genuine Product and Rate Level Estimates for one hundred thirty Nations around the world, 1950–1985,” Evaluation of Cash flow and Wealth 34 (03 1988), pp. one–26CrossRefGoogle https://mancur8873838.tkzblog.com/30293373/a-review-of-mancur88