In the previous part, I focused on conﬂict in EU budgetary politics and argued that the reform of the institutional structure of the decision-making procedure in 1988 was the main reason for a significant reduction in the level of conflict. The institutional setting provided the explanatory (independent) variable that accounted for variation in the level of conﬂict (dependent variable). In this part, I take a different perspective and try to explain the institutional change of 1988. The institutional setting itself will, therefore, become the dependent variable. On the basis of theories of institutional change and path dependence, I will identify a set of explanatory (independent) variables that account for the variation in the stability of institutional settings (dependent variable). I seek to provide an explanation for the mechanisms that ensure institutional stability and the processes that lead to far-reaching changes. For the empirical assessment of my explanation, EU budgetary politics provides two cases of institutional settings that experienced a long period of stability. After years of stability, each case developed differently, the 1970 institutional setting was radically changed by the 1988 reform, while the 1988 institutional setting has remained stable. I will be able to compare the two periods of stability and to detect the differences that eventually split the two cases of stability, resulting in change in the 1970 case and continuous stability in the 1988 case.