As early as 1991 Brown reconceptualized the three elements of sustainable development into four: ecological, economic, political, and cultural. Brown argued that sustainable development was at base an institutional problem and dependent in part on institutional factors. The development process requires the building of social institutions that are sustainable and just. "When such institutions do not exist, infusions of capital, and other resources may fatten the bank accounts of the rich and powerful rather than catalyze development for the poor" (Brown, 1991, p. 4.). Whereas the social dimension of sustainable development refers to the aggregate of human capabilities (or human capital), the institutional dimension refers to the institutions of society and the role their institutional capacities (or social capital) must play to achieve sustainable development. (Valentin & Spangenberg, 2000). Adding an institutional dimension to the three pillar model, we can depict sustainable development as a prism with four nodes as in the model in Figure 4.