The causes of such issues are therefore both institutional and political (OECD, 2016a). For example, in 2015, MOC worked with the Global Green Growth Institute (GGGI) to develop a comprehensive set of Urban Green Growth Indicators, with 40 indicators under four categories: environmental sustainability, economic sustainability, social inclusion, and institutional responsiveness. The indicators span across key green growth sectors including energy, w'ater, air quality, waste and transport (Table 3.5).