title: Discussion of "Semiparametric Estimation of Treatment Effect in a Pretest-Posttest Study With Missing Data" by Davidian, Tsiatis and Leon.
authors.affiliation: Department of Statistics and The Methodology Center, The Pennsylvania State University, University Park, PA 16802.
authors.forename: Joseph L
authors.initials: JL
authors.lastname: Schafer
authors.forename: Joseph D Y
authors.initials: JD
authors.lastname: Kang