When and how do ordinary citizens gain substantial control over important collective decisions affecting their lives? This book provides new answers to this question by systematically accumulating evidence in novel ways. From calls for ‘no taxation without representation’ to ‘defunding the police’, questions regarding the authority to make and implement public spending decisions have played an important role in the imagination and practice of democracy. It is perhaps no surprise, then, that the idea and practice of participatory budgeting (PB), expanding the ‘power of the purse’, has garnered such interest. PB has been widely implemented by committed reformers in politics, bureaucracies and civil society, and has been studied by a number of committed scholars. The research I present here offers critical insights into when and how PB programmes succeed and fail in increasing democracy by allowing citizens greater influence over collective decisions. The work is based on bringing together the work of other scholars as well as providing a more systematic investigation of existing claims about PB using advanced comparative methods. Rather than search for further ‘unique’ examples of public policy innovations in the field, I bring together existing research that, in the end, provides unique insights that can only be found through such a procedure.

I show that popular claims that there are several single necessary conditions for citizens to gain such control over collective decisions have been imprudent. Successes (and, for that matter, failure) can be demonstrated where conditions that have been touted as necessary are both present and absent. Nevertheless, a political leadership committed to participation is almost always required for sustained citizen control of political decisions over the longer term. The meaningful involvement of citizens in collective governance often requires a combination of will and capacity to implement programmes from political leaders, but there is evidence that these good outcomes only occur where those willing leaders can rely on strong support and competence from administrative staff, or alternatively, where participatory leaders have strong fiscal independence. Perhaps controversially, the evidence for the importance of civil society conditions, which have played a strong role in theories of successful citizen participation, is mixed. Whether civil society is relevant to explanations of successful participation depends on the level of uncertainty that researchers are willing to accept in their theories, and reveals issues of conceptualization of civil society roles in participatory programmes.