“…There is a tendency to assume that RCTs can establish 'what works'. However, as a number of commentators have argued elsewhere, such trials are not necessarily suited to answering the 'what works' question when applied to social policy unless a long list of qualifications is added and addressed (e.g., see Reiss, 2007Reiss, , 2014Deaton, 2009;Cartwright, 2010;Favereau, 2016;Deaton & Cartwright, 2017). As Cartwright and Hardie (2012) have pointed out, RCTs generally establish not 'what works', but only that something worked, at some place, at that time.…”