The Role of the Propensity Score in Estimating Dose-Response Functions

22 Pages Posted: 11 Jun 2000 Last revised: 25 Feb 2024

See all articles by Guido W. Imbens

Guido W. Imbens

Stanford Graduate School of Business

Date Written: April 1999

Abstract

Estimation of average treatment effects in observational, or non-experimental in pre-treatment variables. If the number of pre-treatment variables is large, and their distribution varies substantially with treatment status, standard adjustment methods such as covariance adjustment are often inadequate. Rosenbaum and Rubin (1983) propose an alternative method for adjusting for pre-treatment variables based on the propensity score conditional probability of receiving the treatment given pre-treatment variables. They demonstrate that adjusting solely for the propensity score removes all the bias associated with differences in pre-treatment variables between treatment and control groups. The Rosenbaum-Rubin proposals deal exclusively with the case where treatment takes on only two values. In this paper an extension of this methodology is proposed that allows for estimation of average causal effects with multi-valued treatments while maintaining the advantages of the propensity score approach.

Suggested Citation

Imbens, Guido W., The Role of the Propensity Score in Estimating Dose-Response Functions (April 1999). NBER Working Paper No. t0237, Available at SSRN: https://ssrn.com/abstract=226648

Guido W. Imbens (Contact Author)

Stanford Graduate School of Business ( email )

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