Rejoinder: Demystifying Double Robustness: A Comparison of Alternative Strategies for Estimating a Population Mean from Incomplete Data

We are grateful to the editors for eliciting comments from some of the most prominent researchers in this exciting and rapidly developing field. After we drafted our article, a number of important works on DR estimators appeared, including Tan’s (2006) article on causal inference, the monograph by Tsiatis (2006) and the recent articles and technical reports cited by Robins, Sued, Lei-Gomez and Rotnitzky. The discussants’ insightful remarks highlight these recent developments and bring us up to date. Our purpose in writing this article was to provide unfamiliar readers with gentle introduction to DR estimators without the language of influence functions, using only simple concepts from regression analysis and survey inference. We wanted to show that DR estimators come in many different flavors. And, without minimizing the importance of the literature spawned by Robins, Rotnitzky and Zhao (1994), we wanted to draw attention to some older related methods from model-assisted survey sampling which arrive at a similar position from the opposite direction.