Discussion of "The Blessings of Multiple Causes" by Wang and Blei

We begin by congratulating Yixin Wang and David Blei for their thought-provoking article that opens up a new research frontier in the field of causal inference. The authors directly tackle the challenging question of how to infer causal effects of many treatments in the presence of unmeasured confounding. We expect their article to have a major impact by further advancing our understanding of this important methodological problem. This commentary has two goals. We then briefly consider three possible ways to address some of the limitations of the deconfounder method. We first discuss several advantages offered by the deconfounder method. We then examine the assumptions required by the method and discuss its limitations.