The identification of many potential conditions that could explain success in PB is not unhelpful. Brian Wampler's analysis of eight participatory budgets in urban Brazil, for example, has been a particularly useful contribution for scholars who wish to explain the emergence of emancipatory participatory governance through democratic innovation (2007a). Therefore, I use this as an access point in the following chapters to help explain how we might improve our theories by systematically navigating cumulation of more studies. I begin with a slightly stylized QCA of Wampler's most minimal account of deepened democracy to help establish what is at stake in set-theoretic analysis, and introduce methodological aspects gradually for unfamiliar readers. I then expand on this briefly, to show how QCA provides nuance for his most comprehensive account, before presenting the results of the more comprehensive analysis cumulating the work of several scholars.

Despite the quality of earlier work, without a more ecumenical but also systematic comparison it can be too tempting to generalize conditions particular to one context as necessary to others. In this part of the book I demonstrate to those familiar with the field the benefit of enhanced comparative approaches. I show that a more systematic comparison of diverse cases provides evidence that PB processes can be successful in very different contexts. This is a major finding because it lowers the barriers to the adoption of PB by offering policymakers options rather than a long list of requirements in policy formulation. This is not to say anything goes. I identify the most plausible conditions in alternative contexts for achieving or negating successful citizen control in PB programmes.