隨著地球村程度的日益加深，企業在考量跨國投資決策時，傳統以匯率做為不同貨幣之間的簡單換算，未考量到各國貨幣購買力的差異，而可能導致未能形成最適決策。
本研究資料來源為OECD，以七大工業國的國內生產毛額與醫療產業研發投入為研究對象，探討「購買力平價」與常見之3種調整方法，衡量實質經濟規模之效果差異。研究分析方法採用關聯性分析、主成份分析與驗證型因素分析等多變量方法進行實證研析，資料來源為。
研究結果顯示：
1. 就GDP觀察，七大工業國中，除義大利及英國外，衡量實質經濟規模的最佳方式是「當期價格、以原始貨幣表示」，次佳方式則為「固定基期價格、以原始貨幣表示」及「購買力平價、以美元表示」，此二調整方式與最佳方式之差異不大，另「依匯率折算為美元」的調整方法最不適宜用來衡量實質GDP。
2. 由醫療產業研發投入觀察，除加拿大、法國外，七大工業國衡量該產業實質研發投入之最佳指標則為「購買力平價、以美元表示」，次為「固定基期價、以原始貨幣表示」，值得一提的是，「依匯率折算為美元」的調整方法，在醫療產業研發投入之4種調整方法中排名第3，超越最適衡量七大工業國實質GDP規模的「當期價格、以原始貨幣表示」。
本研究發現，在同時考慮GDP及醫療產業研發投入實質規模時，七大工業國的最適調整方法應為「購買力平價法」，而常見依匯率直接折算的方法，則為本研究4種調整方式中，最不適合用來衡量實質規模的方法。

Using health data of G7, released by OECD, we tried to analyze and describe which is the best index measuring the real economic development. In this article we compare the correlation of data of the four indices and “real status”. The main analyzing tools are Pearson Correlation Analysis, Principal Component Analysis (PCA) and Confirmatory Factor Analysis (CFA). Listed below are the outcomes of our conclusion:
1. On the part of GDP, besides Italy and United Kingdom, although the best way to compute real domestic output for the rest G7 countries is “national currency, current price”, “national currency, fixed price” and PPP are also very closed to real status. In addition, using exchange rate to convert national currency as US dollars is the worst measuring way.
2. As far as pharmaceutical industry R&D is concerned, using PPP to estimate the real development is the best compare with other three indices.
In conclusion, while GDP and pharmaceutical industry R&D are taking into consideration at the same time, PPP would be the better way measuring the real economic development.

參考文獻
中文部份：
論文、期刊、專書類
1. 宋欽增，「統計實務」，民國87年9月。
2. 李金泉，「SAS/PC+實務與應用統計分析」，松崗，民國83年11月。
3. 陳昌雄，「出席亞太國際比較計畫(ICP)各國統計主管會議報告」，行政院及其所屬各機關出國報告，民國92年9月。
4. 陳順宇，「多變量分析」，華泰，民國93年1月。
5. 黃登源，「應用多變量分析」講義，輔仁大學應用統計研究所。
6. 張紹勳、林秀娟，「SAS/PC統計分析與實務應用」，松崗，民國84年1月。
7. 謝登隆、徐繼達，「總體經濟理論與政策」，智勝，民國90年1月。
報紙雜誌類
1. 台灣地區物價統計月報，行政院主計處，民國93年12月。
英文部份：
1. Abuaf, N. and P. Jorion. 1990. “Purchasing Power Parity in the Long Run.” Journal of Finance. 45: pp.157-74.
2. Adler, Michael and Bruce Lehmann. 1983. “Deviations from Purchasing Power Parity in the Long Run.” Journal of Finance. 38:5, pp. 1471-87.
3. Balassa, Bela. 1964. “The Purchasing Power Parity Doctrine: A Reappraisal.” Journal of Political Economy. 72, pp. 584-96.
4. Cassel, Gustav. 1918. “Abnormal Deviations in International Exchanges.” Economic Journal. 28, pp.413-15.
5. Dornbusch, Rudiger. 1976. “Expectations and Exchange Rate Dynamics.” Journal of Political Economy. 84:6, pp. 1161-76.
6. Edison, Hali J. 1987. “Purchasing Power Parity in the Long Run: A Test of the Dollar/Pound Exchange Rate. 1890-1978.” Journal of Money, Credit and Banking. 19:3, pp. 376-87.
7. Frankel, Jaffrey A. 1986. “International Capital Mobility and Crowding-out in the U.S. Economy: Imperfect Integration of Financial Markets or of Goods Markets.” in How Open is the U.S. Economy? R.W. Hafer ed. Lexington, Mass.: Lexington Books, pp. 33-67.
8. Frenkel, Jacob A. 1981. “The collapse of Purchasing Power Parity During the 1970s." European Economic Review. 16, pp. 145-65.
9. Froot, Kenneth A. and Kenneth Rogoff. 1995. “Perspectives on PPP and Long-Run Real Exchange Rates.” in Handbook of International Economics. G. Grossman and K. Rogoff, eds. Amsterdam: North Holland, pp. 1647-88.
10. Hakkio, C. 1984. “A Reexamination of Purchasing Power Parity.” Journal of International Economics. 17: 265-277.
11. Joseph F. Hair, JR., Rolph E. Anderson, Ronald L. Tatham, William C.Black. “Multivariate Data Analysis”. Prentice-Hall. 5th edition.
12. Lothian, James R. and Mark. P. Taylor. 1997. “Real Exchange Rate Behavior: The Recent Float From the Perspective of the Past Two Centuries.” Journal of Political Economy. 104:3, pp. 488-509.
13. Luintel, K. B. 2000. “Real Exchange Rate Behaviour: Evidence from Black Markets.” Journal of Applied Econometrics. 15: 161-85.
14. Papell, D.H. and H. Theodoridis. 1998. “Increasing Evidence of Purchasing Power Parity over the Current Float.” Journal of International Money and Finance. 17: 41-50.
15. Phylaktis, K. and Y. Kassimatis. 1994. “Does the Real Exchange Rate Follow a Random Walk? The Pacific Basin Perspective.” Journal of International Money and Finance. 13: 476-95.
16. Samuelson, Paul A. 1964. “Theoretical Notes on Trade Problems.” Review of Economics and Statistics. 46, pp. 145-54.
17. Wei, S. and D. Parsley. 1995. “Purchasing Power Disparity during the Floating Rate Period: Exchange Rate Volatility and Trade Barriers.” NBER Working Paper No. 5032. Massachusetts: National Bureau of Economic Research.
18. Yotopoulos, Pan A. and Jenn-Yih Lin. 1993. “Purchasing Power Parities for Taiwan: The Basic Data for 1985 and International Comparisons.” Journal of Economic Development. Korea, No.1.
網站：
1. OECD，http://www.oecd.org/
2. 中華民國中東歐暨獨立國協經貿協會，http://ceeca.taiwantrade.org.tw/
3. 世界銀行，http://www.worldbank.org/
4. 世界貿易組織，http://www.wto.org/
5. 行政院主計處，http://www.stat.gov.tw/
6. 美國賓州大學國際比較中心，http://pwt.econ.upenn.edu/
7. 經濟部，http://www.moea.gov.tw/