How many RCT studies did the authors analyse to inform their findings and conclusions?
Editors: Hundreds. Each of the 12 chapters quotes dozens, focused on different issues (see the extended references section at the end of the book). Each chapter is based on a certain number of studies, either with an exhaustive view (e.g. the chapter on global health) or focusing on the most vocal studies (e.g. the chapters on sanitation and microcredit). In this case it is not the number that matters, but the influence that these studies have had on the field. Moreover, when the objective is to analyze the theoretical weaknesses of the method, the number does not matter.
Lant: I have seen and read RCTs for a long time. In fact, by a twist of fate, I was the responsible World Bank task manager for one of Michael Kremer’s first RCTs (about textbooks). In a field in which I work closely (education economics) I have read dozens. In addition, I have read summaries of this both in education and more generally (e.g. Vivalt). So, a lot, enough to I think have a good sense of how they have, or have not, contributed to my fields and to development more generally.