This chapter develops an original “theory of change” that connects PB programs to three community-level outcomes: the promotion of accountability, expansion of civil society, and improvements in well-being. To explain the variation in outcomes, this explanatory framework includes macro-level (political context, decentralization, economic conditions) and meso-level (government support, configuration of civil society, state capacity) factors that condition PB programs’ impacts. The discussion then moves beyond the macro and meso to drill down to “variation in program design.” The chapter identifies several rules (scale/level of adoption, presence of social justice rules, program emphasis on social inclusion, vote rules, and oversight process) that significantly influence the outcomes that PB programs produce. Thus, this chapter illuminates how variation in the macro, meso, and PB design rules condition and constrain the types of outcomes associated with PB. The chapter concludes by linking the theory of change to the PB Types (introduced in Chapter 1) to theorize how each PB program type is likely to be associated with distinct impacts.