To Smooth or Not to Smooth? The Case of Discrete Variables in Nonparametric Regressions
In a seminal paper, Racine and Li, (Journal of Econometrics, 2004) introduce a tool which admits discrete and categorical variables as regressors in nonparametric regres- sions. The method is similar to the smoothing techniques for continuous regressors but uses discrete kernels. In the literature, it is generally admitted that it is always better to smooth the discrete variables. In this paper we investigate the potential problem linked to the bandwidths selection for the continuous variable due to the presence of the discrete variables. We find that in some cases, the performance of the resulting regression estimates may be deteriorated by smoothing the discrete variables in the way addressed so far in the literature, and that a fully separate estimation (without any smoothing of the discrete variable) may provide significantly better results, and we explain why this may happen. The problem being posed, we then suggest how to use the Racine and Li approach to overcome these difficulties and to provide estimates with better performances. We investigate through some simulated data sets and by more ex- tensive Monte-Carlo experiments the performances of all the proposed approaches and we find that, as expected, our suggested approach has the best performances. We also briefly illustrate the consequences of these issues on the estimation of the derivatives of the regression. Finally, we exemplify the phenomenon with an empirical illustration. Our main objective is to warn the practitioners of the potential problems posed by smoothing discrete variables by using the so far available softwares and to suggest a safer approach to implement the procedure.
|Date of creation:||2011|
|Date of revision:|
|Contact details of provider:|| Postal: St. Lucia, Qld. 4072|
Phone: +61 7 3365 6570
Fax: +61 7 3365 7299
Web page: http://www.uq.edu.au/economics/
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.:
- Pagan,Adrian & Ullah,Aman, 1999.
Cambridge University Press, number 9780521355643, Junio.
- W. Walls, 2009. "Screen wars, star wars, and sequels," Empirical Economics, Springer, vol. 37(2), pages 447-461, October.
- Byeong U. Park & Leopold Simar & Valentin Zelenyuk, 2010. "Local Maximum Likelihood Techniques with Categorical Data," CEPA Working Papers Series WP142010, School of Economics, University of Queensland, Australia.
- Maasoumi, Esfandiar & Racine, Jeff, 2006.
"Growth And Convergence: A Profile Of Distribution Dynamics And Mobility,"
Departmental Working Papers
0605, Southern Methodist University, Department of Economics.
- Maasoumi, Esfandiar & Racine, Jeff & Stengos, Thanasis, 2007. "Growth and convergence: A profile of distribution dynamics and mobility," Journal of Econometrics, Elsevier, vol. 136(2), pages 483-508, February.
- Thanasis Stengos & Eleftherios Zaharias, 2002.
"Intertemporal Pricing and Price Discrimination: A Semiparametric Hedonic Analysis of the Personal Computer Market,"
University of Cyprus Working Papers in Economics
0211, University of Cyprus Department of Economics.
- E. Zacharias & T. Stengos, 2006. "Intertemporal pricing and price discrimination: a semiparametric hedonic analysis of the personal computer market," Journal of Applied Econometrics, John Wiley & Sons, Ltd., vol. 21(3), pages 371-386.
- Stengos, T. & Zacharias, E., 2003. "Intertemporal Pricing and Price Discrimination: A Semiparametric Hedonic Analysis of the Personal Computer Market," Working Papers 2003-9, University of Guelph, Department of Economics and Finance.
- Jeffery Racine & Jeffrey Hart & Qi Li, 2006. "Testing the Significance of Categorical Predictor Variables in Nonparametric Regression Models," Econometric Reviews, Taylor & Francis Journals, vol. 25(4), pages 523-544.
- Racine, Jeff & Li, Qi, 2004. "Nonparametric estimation of regression functions with both categorical and continuous data," Journal of Econometrics, Elsevier, vol. 119(1), pages 99-130, March.
- Peter Hall & Qi Li & Jeffrey S. Racine, 2007. "Nonparametric Estimation of Regression Functions in the Presence of Irrelevant Regressors," The Review of Economics and Statistics, MIT Press, vol. 89(4), pages 784-789, November.
- Daniel J. Henderson & Valentin Zelenyuk, 2007. "Testing for (Efficiency) Catching-up," Southern Economic Journal, Southern Economic Association, vol. 73(4), pages 1003–1019, April.
- Eren,Ozkan & Henderson,J. Daniel, 2006.
"The Impact of Homework on Student Achievement,"
Departmental Working Papers
0518, Southern Methodist University, Department of Economics, revised 12 May 2006.
- Daniel J. Henderson & Christopher F. Parmeter & Subal C. Kumbhakar, 2007. "Nonparametric estimation of a hedonic price function," Journal of Applied Econometrics, John Wiley & Sons, Ltd., vol. 22(3), pages 695-699.
- Subodh Kumar & R. Robert Russell, 2002. "Technological Change, Technological Catch-up, and Capital Deepening: Relative Contributions to Growth and Convergence," American Economic Review, American Economic Association, vol. 92(3), pages 527-548, June.
- Oleg Badunenko & Daniel J. Henderson & Valentin Zelenyuk, 2008.
"Technological Change and Transition: Relative Contributions to Worldwide Growth During the 1990s,"
Oxford Bulletin of Economics and Statistics,
Department of Economics, University of Oxford, vol. 70(4), pages 461-492, 08.
- Oleg Badunenko & Daniel J. Henderson & Valentin Zelenyuk, 2007. "Technological Change and Transition: Relative Contributions to Worldwide Growth during the 1990s," Discussion Papers of DIW Berlin 740, DIW Berlin, German Institute for Economic Research.
- Gozalo, Pedro & Linton, Oliver, 2000. "Local nonlinear least squares: Using parametric information in nonparametric regression," Journal of Econometrics, Elsevier, vol. 99(1), pages 63-106, November.
- Simar, Leopold & Zelenyuk, Valentin, 2004.
"On testing equality of distributions of technical efficiency scores,"
28003, University Library of Munich, Germany.
- Leopold Simar & Valentin Zelenyuk, 2006. "On Testing Equality of Distributions of Technical Efficiency Scores," Econometric Reviews, Taylor & Francis Journals, vol. 25(4), pages 497-522.
- Valentina Hartarska & Christopher F. Parmeter & Denis Nadolnyak, 2010. "Economies of Scope of Lending and Mobilizing Deposits in Microfinance Institutions: A Semiparametric Analysis," American Journal of Agricultural Economics, Agricultural and Applied Economics Association, vol. 93(2), pages 389-398.
- Hsiao, Cheng & Li, Qi & Racine, Jeffrey S., 2007.
"A consistent model specification test with mixed discrete and continuous data,"
Journal of Econometrics,
Elsevier, vol. 140(2), pages 802-826, October.
- Cheng Hsiao & Qi Li & Jeff Racine, 2006. "A Consistent Model Specification Test with Mixed Discrete and Continuous Data," IEPR Working Papers 06.47, Institute of Economic Policy Research (IEPR).
- Daniel J. Henderson & R. Robert Russell, 2005. "Human Capital And Convergence: A Production-Frontier Approach ," International Economic Review, Department of Economics, University of Pennsylvania and Osaka University Institute of Social and Economic Research Association, vol. 46(4), pages 1167-1205, November.
- Qi Li & Jeffrey Scott Racine, 2006. "Nonparametric Econometrics: Theory and Practice," Economics Books, Princeton University Press, edition 1, number 8355, 06-2016.
- Daniel J. Henderson, 2010. "A test for multimodality of regression derivatives with application to nonparametric growth regressions," Journal of Applied Econometrics, John Wiley & Sons, Ltd., vol. 25(3), pages 458-480.
When requesting a correction, please mention this item's handle: RePEc:qld:uqcepa:76. 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: (SOE IT)
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 references are entirely missing, you can add them using this form.
If the full references list an item that is present in RePEc, but the system did not link 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 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.