title: Discussion of "Identifiability and estimation of causal effects in randomized trials with noncompliance and completely nonignorable missing data".
authors.affiliation: Department of Statistics, The Wharton School, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA. dsmall@wharton.upenn.edu
authors.forename: Dylan S
authors.initials: DS
authors.lastname: Small
authors.forename: Jing
authors.initials: J
authors.lastname: Cheng