“…Firstly, the cited conclusion neglects the results of several PWYW studies, which detect no significant associations between the level or the use of external RP and prices paid (Gautier & Van der Klaauw, 2012 (in case of self-selected PWYW participation of customers); Gneezy et al, 2012;Hildenbrand et al, 2016; (in case of field studies on actual prices paid); Weisstein et al, 2016) or even find significantly negative correlations, particularly if the external RP was displayed as a minimal threshold value (Johnson & Cui, 2013; (study 12a); Kunter & Braun, 2013;Racherl et al, 2011;Roy et al, 2016a;Thomas & Gierl, 2014). Secondly, it ignores that significantly positive effects of external RP are mainly observed in studies which are highly problematic in terms of their methodology, because they focus on hypothetical payments of students, whereas field studies of real purchases almost never report such effects (Jung et al, 2016, p. 356).…”