31. Its component expenditures are based on purchasing power parities ( PPP both currency converters and spatial price deflators. 32. What does Purchasing power parity mean? 33. In 1982, Ward joined the OECD full-time and made the first OECD-Eurostat purchasing power parity calculations for 1980. 34. The yuan is estimated to be 4 per cent overvalued against the US dollar on purchasing power parity , 35. GDP, adjusted for purchasing power parity . 36. At purchasing power parity , the global economic output expanded by US $ 39.1 trillion from 2000 to 2010. 37. Now, though, Singapore's per capita annual income has risen to ninth in the world, adjusted for purchasing power parity . 38. For purchasing power parity comparisons, the U . S . dollar is exchanged at 3.75 Saudi Arabian Riyals only. 39. Robert Summers and Alan Heston ( 1991 ) recalculated the incomes of nations, using estimates of purchasing power parities . 40. It is considered a variation of Purchasing Power Parity , which is an entirely different concept that is economically accepted.