UC Irvine

Mark Bell’s article (2016) is a welcome contribution to the unavoidable task of evaluating a research program that exhibits the problems he identifies: the failure of most quantitative studies to offer strong explanations for proliferation patterns, and their inability to predict out-of-sample cases. His findings resonate with those of other proliferation experts. The existing quantitative literature, argues Bell, produces more tentative findings than scholars typically understand. We concur fully with the first part of the last sentence but believe that the broader community of experts typically􀀁does􀀁understand the serious limitations of most quantitative studies (and qualitative ones) on this topic.