Improving the CPI’s Age-Bias Adjustment: Leverage, Disaggregation and Model Averaging
As a rental unit ages, its quality typically falls; a failure to correct for this would result in downward bias in the CPI. We investigate the BLS age bias imputation and explore two potential categories of error: approximations related to the construction of the age bias factor, and model mis-specification. We find that, as long as one stays within the context of the current official regression specification, the approximation errors are innocuous. On the other hand, we find that the official regression specification – which is more or less of the form commonly used in the hedonic rent literature – is severely deficient in its ability to match the conditional log-rent vs. age relationship in the data, and performs poorly in out-of-sample tests. It is straightforward to improve the specification in order to address these deficiencies. However, basing estimates upon a single regression model is risky. Age-bias adjustment inherently suffers from a general problem facing some types of hedonic-based adjustments, which is related to model uncertainty. In particular, age-bias adjustment relies upon specific coefficient estimates, but there is no guarantee that the true marginal influence of a regressor is being estimated in any given model, since one cannot guarantee that the Gauss-Markov conditions hold. To address this problem, we advocate the use of model averaging, which is a method that minimizes downside risks related to model misspecification and generates more reliable coefficient estimates. Thus, after selecting several appropriate models, we estimate age-bias factors by taking a trimmed average over the factors derived from each model. We argue that similar methods may be readily implemented by statistical agencies (even very small ones) with little additional effort. We find that, in 2004 data, BLS age-bias factors were too small, on average, by nearly 40%. Since the age bias term itself is rather small, the implied downward-bias of the aggregate indexes is modest. On the other hand, errors in particular metropolitan areas were much larger, with annual downward-bias as large as 0.6%.
|Date of creation:||Oct 2007|
|Date of revision:|
|Contact details of provider:|| Postal: |
Phone: (202) 606-5900
Fax: (202) 606-7890
Web page: http://www.bls.gov
More information through EDIRC
References listed on IDEAS
Please report citation or reference errors to , or , if you are the registered author of the cited work, log in to your RePEc Author Service profile, click on "citations" and make appropriate adjustments.:
- Francis X. Diebold & Peter Pauly, 1987.
"The use of prior information in forecast combination,"
Special Studies Papers
218, Board of Governors of the Federal Reserve System (U.S.).
- Diebold, Francis X. & Pauly, Peter, 1990. "The use of prior information in forecast combination," International Journal of Forecasting, Elsevier, vol. 6(4), pages 503-508, December.
- Mark W. Watson & James H. Stock, 2004. "Combination forecasts of output growth in a seven-country data set," Journal of Forecasting, John Wiley & Sons, Ltd., vol. 23(6), pages 405-430.
- Carmen Fernandez & Eduardo Ley & Mark F. J. Steel, 2001.
"Model uncertainty in cross-country growth regressions,"
Journal of Applied Econometrics,
John Wiley & Sons, Ltd., vol. 16(5), pages 563-576.
- Carmen Fernandez & Eduardo Ley & Mark Steel, 2001. "Model uncertainty in cross-country growth regressions," Econometrics 0110002, EconWPA.
- Carmen Fernandez & Eduardo Ley & Mark Steel, 1999. "Model uncertainty in cross-country growth regressions," Econometrics 9903003, EconWPA, revised 06 Oct 2001.
- Durlauf,S.N. & Johnson,P.A. & Temple,J.R.W., 2004.
18, Wisconsin Madison - Social Systems.
- Johnson, Paul & Durlauf, Steven N & Temple, Johnathan R. W., 2004. "Growth Econometrics," Vassar College Department of Economics Working Paper Series 61, Vassar College Department of Economics.
- Brock,W.A. & Durlauf,S.N. & West,K.D., 2003.
"Policy evaluation in uncertain economic environments,"
15, Wisconsin Madison - Social Systems.
- William A. Brock & Steven N. Durlauf & Kenneth D. West, 2003. "Policy Evaluation in Uncertain Economic Environments," Brookings Papers on Economic Activity, Economic Studies Program, The Brookings Institution, vol. 34(1), pages 235-322.
- William A. Brock & Steven N. Durlauf & Kenneth D. West, 2003. "Policy Evaluation in Uncertain Economic Environments," NBER Working Papers 10025, National Bureau of Economic Research, Inc.
- Clemen, Robert T., 1989. "Combining forecasts: A review and annotated bibliography," International Journal of Forecasting, Elsevier, vol. 5(4), pages 559-583.
- Danilov, D.L. & Magnus, J.R., 2002.
"Forecast Accuracy after Pretesting with an Application to the Stock Market,"
2002-76, Tilburg University, Center for Economic Research.
- Jan R. Magnus & Dmitry Danilov, 2004. "Forecast accuracy after pretesting with an application to the stock market," Journal of Forecasting, John Wiley & Sons, Ltd., vol. 23(4), pages 251-274.
- Temple, Jonathan, 2000. "Growth Regressions and What the Textbooks Don't Tell You," Bulletin of Economic Research, Wiley Blackwell, vol. 52(3), pages 181-205, July.
- Eklund, Jana & Karlsson, Sune, 2005.
"Forecast Combination and Model Averaging using Predictive Measures,"
Working Paper Series
191, Sveriges Riksbank (Central Bank of Sweden).
- Jana Eklund & Sune Karlsson, 2007. "Forecast Combination and Model Averaging Using Predictive Measures," Econometric Reviews, Taylor & Francis Journals, vol. 26(2-4), pages 329-363.
- Eklund, Jana & Karlsson, Sune, 2005. "Forecast Combination and Model Averaging Using Predictive Measures," CEPR Discussion Papers 5268, C.E.P.R. Discussion Papers.
- Jacobson, Tor & Karlsson, Sune, 2002.
"Finding Good Predictors for Inflation: A Bayesian Model Averaging Approach,"
Working Paper Series
138, Sveriges Riksbank (Central Bank of Sweden).
- Sune Karlsson & Tor Jacobson, 2004. "Finding good predictors for inflation: a Bayesian model averaging approach," Journal of Forecasting, John Wiley & Sons, Ltd., vol. 23(7), pages 479-496.
- Gernot Doppelhofer & Ronald I. Miller & Xavier Sala-i-Martin, 2000.
"Determinants of Long-Term Growth: A Bayesian Averaging of Classical Estimates (BACE) Approach,"
NBER Working Papers
7750, National Bureau of Economic Research, Inc.
- Xavier Sala-I-Martin & Gernot Doppelhofer & Ronald I. Miller, 2004. "Determinants of Long-Term Growth: A Bayesian Averaging of Classical Estimates (BACE) Approach," American Economic Review, American Economic Association, vol. 94(4), pages 813-835, September.
- Gernot Doppelhofer & Ronald I. Miller & Xavier Sala-i-Martin, 2000. "Determinants of Long-Term Growth: A Bayesian Averaging of Classical Estimates (Bace) Approach," OECD Economics Department Working Papers 266, OECD Publishing.
- Marco Aiolfi & Carlos Capistrán & Allan Timmermann, 2010.
CREATES Research Papers
2010-21, School of Economics and Management, University of Aarhus.
- David Hendry & Michael Clements, 2001.
"Pooling of Forecasts,"
Economics Series Working Papers
2002-W09, University of Oxford, Department of Economics.
- Gary Koop & Simon Potter, 2003.
"Forecasting in large macroeconomic panels using Bayesian Model Averaging,"
163, Federal Reserve Bank of New York.
- Gary Koop & Simon Potter, 2003. "Forecasting in Large Macroeconomic Panels using Bayesian Model Averaging," Discussion Papers in Economics 04/16, Department of Economics, University of Leicester.
- repec:cup:etheor:v:7:y:1991:i:2:p:163-85 is not listed on IDEAS
- Swanson, Norman R & Zeng, Tian, 2001. "Choosing among Competing Econometric Forecasts: Regression-Based Forecast Combination Using Model Selection," Journal of Forecasting, John Wiley & Sons, Ltd., vol. 20(6), pages 425-40, September.
- Steven B. Caudill & Randall G. Holcombe, 1999. "Specification Search and Levels of Significance in Econometric Models," Eastern Economic Journal, Eastern Economic Association, vol. 25(3), pages 289-300, Summer.
- Jan R. Magnus & J. Durbin, 1999. "Estimation of Regression Coefficients of Interest When Other Regression Coefficients Are of No Interest," Econometrica, Econometric Society, vol. 67(3), pages 639-644, May.
- Theodore M. Crone & Leonard I. Nakamura & Richard Voith, 2010.
"Rents Have Been Rising, Not Falling, in the Postwar Period,"
The Review of Economics and Statistics,
MIT Press, vol. 92(3), pages 628-642, August.
- Theodore Crone & Leonard I. Nakamura & Richard Voith, 2008. "Rents have been rising, not falling, in the postwar period," Working Papers 08-28, Federal Reserve Bank of Philadelphia.
- Yang, Yuhong, 2004. "Combining Forecasting Procedures: Some Theoretical Results," Econometric Theory, Cambridge University Press, vol. 20(01), pages 176-222, February.
- Pesaran, M. Hashem & Timmermann, Allan, 2007. "Selection of estimation window in the presence of breaks," Journal of Econometrics, Elsevier, vol. 137(1), pages 134-161, March.
- repec:cup:etheor:v:11:y:1995:i:3:p:537-49 is not listed on IDEAS
- Pötscher, B.M., 1991. "Effects of Model Selection on Inference," Econometric Theory, Cambridge University Press, vol. 7(02), pages 163-185, June.
- Kabaila, Paul, 1995. "The Effect of Model Selection on Confidence Regions and Prediction Regions," Econometric Theory, Cambridge University Press, vol. 11(03), pages 537-549, June.
- Granger, Clive W. J. & Jeon, Yongil, 2004. "Thick modeling," Economic Modelling, Elsevier, vol. 21(2), pages 323-343, March.
When requesting a correction, please mention this item's handle: RePEc:bls:wpaper:ec070100. 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: (Gregory Kurtzon)
If references are entirely missing, you can add them using this form.