IDEAS home Printed from
   My bibliography  Save this paper

The Hedonic Country Product Dummy Method and Quality Adjustments for Purchasing Power Parity Calculations


  • Mick Silver


The 2005 International Comparison Program's (ICP) estimates of economy-wide purchasing power parity (PPP) are based on parity estimates for 155 basic expenditure headings, mainly estimated using country product dummy (CPD) regressions. The estimates are potentially inefficient and open to omitted variable bias for two reasons. First, they use average prices across outlets as the left-hand-side variable. Second, quality-adjusted prices of non-comparable replacements, required when products in outlets do not match the required specifications, cannot be effectively included. This paper provides an analytical framework based on panel data and hedonic CPD regressions for ameliorating these sources of bias and inefficiency.

Suggested Citation

  • Mick Silver, 2009. "The Hedonic Country Product Dummy Method and Quality Adjustments for Purchasing Power Parity Calculations," IMF Working Papers 09/271, International Monetary Fund.
  • Handle: RePEc:imf:imfwpa:09/271

    Download full text from publisher

    File URL:
    Download Restriction: no

    References listed on IDEAS

    1. Baltagi, Badi H., 1981. "Pooling : An experimental study of alternative testing and estimation procedures in a two-way error component model," Journal of Econometrics, Elsevier, vol. 17(1), pages 21-49, September.
    2. D. S. Prasada Rao, 2005. "On The Equivalence Of Weighted Country-Product-Dummy (Cpd) Method And The Rao-System For Multilateral Price Comparisons," Review of Income and Wealth, International Association for Research in Income and Wealth, vol. 51(4), pages 571-580, December.
    3. W. Erwin Diewert & Saeed Heravi & Mick Silver, 2009. "Hedonic Imputation versus Time Dummy Hedonic Indexes," NBER Chapters,in: Price Index Concepts and Measurement, pages 161-196 National Bureau of Economic Research, Inc.
    4. Chen, Yi Vivian & Heston, Alan & Lipsey, Robert, 2000. "International and interarea comparisons of income, output and prices," Journal of Asian Economics, Elsevier, vol. 11(3), pages 363-364, December.
    5. Silver, Mick & Heravi, Saeed, 2005. "A Failure in the Measurement of Inflation: Results From a Hedonic and Matched Experiment Using Scanner Data," Journal of Business & Economic Statistics, American Statistical Association, vol. 23, pages 269-281, July.
    6. Mick Silver & Saeed Heravi, 2006. "Why Elementary Price Index Number Formulas Differ; Price Dispersion and Product Heterogeneity," IMF Working Papers 06/174, International Monetary Fund.
    7. Dhrymes, Phoebus J. & Lleras-Muney, Adriana, 2006. "Estimation of models with grouped and ungrouped data by means of "2SLS"," Journal of Econometrics, Elsevier, vol. 133(1), pages 1-29, July.
    8. Mary F. Kokoski & Brent R. Moulton & Kimberly D. Zieschang, 1999. "Interarea Price Comparisons for Heterogeneous Goods and Several Levels of Commodity Aggregation," NBER Chapters,in: International and Interarea Comparisons of Income, Output, and Prices, pages 123-169 National Bureau of Economic Research, Inc.
    9. Baltagi, Badi H. & Bresson, Georges & Pirotte, Alain, 2003. "Fixed effects, random effects or Hausman-Taylor?: A pretest estimator," Economics Letters, Elsevier, vol. 79(3), pages 361-369, June.
    10. Ariel Pakes, 2003. "A Reconsideration of Hedonic Price Indexes with an Application to PC's," American Economic Review, American Economic Association, vol. 93(5), pages 1578-1596, December.
    11. Evans, William N & Froeb, Luke M & Werden, Gregory J, 1993. "Endogeneity in the Concentration-Price Relationship: Causes, Consequences, and Cures," Journal of Industrial Economics, Wiley Blackwell, vol. 41(4), pages 431-438, December.
    12. Moulton, Brent R., 1986. "Random group effects and the precision of regression estimates," Journal of Econometrics, Elsevier, vol. 32(3), pages 385-397, August.
    13. J. R. Cuthbert & M. Cuthbert, 1988. "On Aggregation Methods of Purchasing Power Parities," OECD Economics Department Working Papers 56, OECD Publishing.
    14. Viliam Druska & William C. Horrace, 2004. "Generalized Moments Estimation for Spatial Panel Data: Indonesian Rice Farming," American Journal of Agricultural Economics, Agricultural and Applied Economics Association, vol. 86(1), pages 185-198.
    15. Baltagi, Badi H & Levin, Dan, 1986. "Estimating Dynamic Demand for Cigarettes Using Panel Data: The Effects of Bootlegging, Taxation and Advertising Reconsidered," The Review of Economics and Statistics, MIT Press, vol. 68(1), pages 148-155, February.
    16. D.S. Prasada Rao, 2004. "The Country-Product-Dummy Method: A Stochastic Approach to the Computation of Purchasing Power Parities in the ICP," CEPA Working Papers Series WP032004, School of Economics, University of Queensland, Australia.
    17. Ernst R. Berndt & Neal J. Rappaport, 2001. "Price and Quality of Desktop and Mobile Personal Computers: A Quarter-Century Historical Overview," American Economic Review, American Economic Association, vol. 91(2), pages 268-273, May.
    18. W. Erwin Diewert, 1999. "Axiomatic and Economic Approaches to International Comparisons," NBER Chapters,in: International and Interarea Comparisons of Income, Output, and Prices, pages 13-107 National Bureau of Economic Research, Inc.
    19. Teekens, R & Koerts, J, 1972. "Some Statistical Implications of the Log Transformation of Multiplicative Models," Econometrica, Econometric Society, vol. 40(5), pages 793-819, September.
    20. Saeed Heravi & Alan Heston & Mick Silver, 2003. "Using Scanner Data to Estimate Country Price Parities: A Hedonic Regression Approach," Review of Income and Wealth, International Association for Research in Income and Wealth, vol. 49(1), pages 1-21, March.
    21. Christos Ioannidis & Mick Silver, 1999. "Estimating exact hedonic indexes: An application to UK television sets," Journal of Economics, Springer, vol. 69(1), pages 71-94, February.
    22. Sickles, Robin C., 2005. "Panel estimators and the identification of firm-specific efficiency levels in parametric, semiparametric and nonparametric settings," Journal of Econometrics, Elsevier, vol. 126(2), pages 305-334, June.
    Full references (including those not matched with items on IDEAS)


    Citations are extracted by the CitEc Project, subscribe to its RSS feed for this item.

    Cited by:

    1. Robert J. Hill & Iqbal Syed, 2010. "Improving International Comparisons of Real Output: The ICP 2005 Benchmark and its Implications for China," Discussion Papers 2010-25, School of Economics, The University of New South Wales.
    2. Martin Ravallion, 2016. "Toward better global poverty measures," The Journal of Economic Inequality, Springer;Society for the Study of Economic Inequality, vol. 14(2), pages 227-248, June.
    3. Mick Silver, 2010. "IMF Applications of Purchasing Power Parity Estimates," IMF Working Papers 10/253, International Monetary Fund.
    4. Robert J. Hill & Iqbal A. Syed, 2012. "Accounting for Unrepresentative Products and Urban-Rural Price Differences in International Comparisons of Real Income: An Application to the Asia-Pacific Region," Graz Economics Papers 2012-07, University of Graz, Department of Economics.
    5. Sakurai, Takeshi & Ralandison, Tsilavo & Takahashi, Kazushi & Arimoto, Yutaka & Kono, Hisaki, 2015. "Is there any premium for unobservable quality? : a hedonic price analysis of the Malagasy rice market," IDE Discussion Papers 504, Institute of Developing Economies, Japan External Trade Organization(JETRO).
    6. Daniel Melser, 2016. "Prices over the business cycle: micro-level evidence from scanner data," Economics Bulletin, AccessEcon, vol. 36(4), pages 1922-1928.


    All material on this site has been provided by the respective publishers and authors. You can help correct errors and omissions. When requesting a correction, please mention this item's handle: RePEc:imf:imfwpa:09/271. See general information about how to correct material in RePEc.

    For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: (Jim Beardow) or (Hassan Zaidi). General contact details of provider: .

    If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.

    If CitEc recognized a reference but did not link an item in RePEc to it, you can help with this form .

    If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your RePEc Author Service profile, as there may be some citations waiting for confirmation.

    Please note that corrections may take a couple of weeks to filter through the various RePEc services.

    IDEAS is a RePEc service hosted by the Research Division of the Federal Reserve Bank of St. Louis . RePEc uses bibliographic data supplied by the respective publishers.