Use of propensity scores in non-linear response models: The case for health care expenditures
Under the assumption of no unmeasured confounders, a large literature exists on methods that can be used to estimating average treatment effects (ATE) from observational data and that spans regression models, propensity score adjustments using stratification, weighting or regression and even the combination of both as in doubly-robust estimators. However, comparison of these alternative methods is sparse in the context of data generated via nonlinear models where treatment effects are heterogeneous, such as is in the case of healthcare cost data. In this paper, we compare the performance of alternative regression and propensity score-based estimators in estimating average treatment effects on outcomes that are generated via non-linear models. Using simulations, we find that in moderate size samples (n= 5000), balancing on estimated propensity scores balances the covariate means across treatment arms but fails to balance higher-order moments and covariances amongst covariates, raising concern about its use in non-linear outcomes generating mechanisms. We also find that besides inverse-probability weighting (IPW) with propensity scores, no one estimator is consistent under all data generating mechanisms. The IPW estimator is itself prone to inconsistency due to misspecification of the model for estimating propensity scores. Even when it is consistent, the IPW estimator is usually extremely inefficient. Thus care should be taken before naively applying any one estimator to estimate ATE in these data. We develop a recommendation for an algorithm which may help applied researchers to arrive at the optimal estimator. We illustrate the application of this algorithm and also the performance of alternative methods in a cost dataset on breast cancer treatment.
|Date of creation:||May 2008|
|Date of revision:|
|Contact details of provider:|| Postal: |
Phone: (0)1904 323776
Fax: (0)1904 323759
Web page: http://www.york.ac.uk/economics/postgrad/herc/hedg/Email:
More information through EDIRC
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.:
- Heckman, James J. & Navarro, Salvador, 2003.
"Using Matching, Instrumental Variables and Control Functions to Estimate Economic Choice Models,"
IZA Discussion Papers
768, Institute for the Study of Labor (IZA).
- James Heckman & Salvador Navarro-Lozano, 2004. "Using Matching, Instrumental Variables, and Control Functions to Estimate Economic Choice Models," The Review of Economics and Statistics, MIT Press, vol. 86(1), pages 30-57, February.
- James J. Heckman & Salvador Navarro-Lozano, 2003. "Using Matching, Instrumental Variables and Control Functions to Estimate Economic Choice Models," NBER Working Papers 9497, National Bureau of Economic Research, Inc.
- Heckman, James & Navarro-Lozano, Salvador, 2003. "Using matching, instrumental variables and control functions to estimate economic choice models," Working Paper Series 2003:4, IFAU - Institute for Evaluation of Labour Market and Education Policy.
- Heckman, James J, 1990. "Varieties of Selection Bias," American Economic Review, American Economic Association, vol. 80(2), pages 313-18, May.
- Rajeev Dehejia, 1999.
"Program Evaluation as a Decision Problem,"
NBER Working Papers
6954, National Bureau of Economic Research, Inc.
- Nandita Mitra & Alka Indurkhya, 2005. "A propensity score approach to estimating the cost-effectiveness of medical therapies from observational data," Health Economics, John Wiley & Sons, Ltd., vol. 14(8), pages 805-815.
- Oaxaca, Ronald, 1973.
"Male-Female Wage Differentials in Urban Labor Markets,"
International Economic Review,
Department of Economics, University of Pennsylvania and Osaka University Institute of Social and Economic Research Association, vol. 14(3), pages 693-709, October.
- Ronald Oaxaca, 1971. "Male-Female Wage Differentials in Urban Labor Markets," Working Papers 396, Princeton University, Department of Economics, Industrial Relations Section..
- Manning, Willard G, et al, 1987. "Health Insurance and the Demand for Medical Care: Evidence from a Randomized Experiment," American Economic Review, American Economic Association, vol. 77(3), pages 251-77, June.
- Mullahy, John, 1998. "Much ado about two: reconsidering retransformation and the two-part model in health econometrics," Journal of Health Economics, Elsevier, vol. 17(3), pages 247-281, June.
- Coyte, Peter C. & Young, Wendy & Croxford, Ruth, 2000. "Costs and outcomes associated with alternative discharge strategies following joint replacement surgery: analysis of an observational study using a propensity score," Journal of Health Economics, Elsevier, vol. 19(6), pages 907-929, November.
- Blough, David K. & Madden, Carolyn W. & Hornbrook, Mark C., 1999. "Modeling risk using generalized linear models," Journal of Health Economics, Elsevier, vol. 18(2), pages 153-171, April.
- James J. Heckman & Jeffrey A. Smith, 1998. "Evaluating the Welfare State," NBER Working Papers 6542, National Bureau of Economic Research, Inc.
- Manning, Willard G. & Mullahy, John, 2001.
"Estimating log models: to transform or not to transform?,"
Journal of Health Economics,
Elsevier, vol. 20(4), pages 461-494, July.
- Willard G. Manning & John Mullahy, 1999. "Estimating Log Models: To Transform or Not to Transform?," NBER Technical Working Papers 0246, National Bureau of Economic Research, Inc.
- Keisuke Hirano & Guido W. Imbens & Geert Ridder, 2000.
"Efficient Estimation of Average Treatment Effects Using the Estimated Propensity Score,"
NBER Technical Working Papers
0251, National Bureau of Economic Research, Inc.
- Keisuke Hirano & Guido W. Imbens & Geert Ridder, 2003. "Efficient Estimation of Average Treatment Effects Using the Estimated Propensity Score," Econometrica, Econometric Society, vol. 71(4), pages 1161-1189, 07.
- Guido Imbens, 2000. "Efficient Estimation of Average Treatment Effects Using the Estimated Propensity Score," Econometric Society World Congress 2000 Contributed Papers 1166, Econometric Society.
- Joshua Angrist & Jinyong Hahn, 2004. "When to Control for Covariates? Panel Asymptotics for Estimates of Treatment Effects," The Review of Economics and Statistics, MIT Press, vol. 86(1), pages 58-72, February.
- Jack Hadley & Daniel Polsky & Jeanne S. Mandelblatt & Jean M. Mitchell & Jane C. Weeks & Qin Wang & Yi-Ting Hwang, 2003. "An exploratory instrumental variable analysis of the outcomes of localized breast cancer treatments in a medicare population," Health Economics, John Wiley & Sons, Ltd., vol. 12(3), pages 171-186.
- Manning, Willard G., 1998. "The logged dependent variable, heteroscedasticity, and the retransformation problem," Journal of Health Economics, Elsevier, vol. 17(3), pages 283-295, June.
- Michael LECHNER, 2008. "A Note on the Common Support Problem in Applied Evaluation Studies," Annales d'Economie et de Statistique, ENSAE, issue 91-92, pages 217-235.
When requesting a correction, please mention this item's handle: RePEc:yor:hectdg:08/11. 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: (Jane Rawlings)
If references are entirely missing, you can add them using this form.