This paper shows a significant and causal positive relationship between good institutions and sustainability. While sustainability is measured with the adjusted net saving (ANS) indicator, institutional quality is measured using an average of six dimensions of governance. An instrumental variable is used to account for endogeneity. Rearranging the set-up and running the regression on the net national savings rate lead to results displaying a much smaller and weaker effect. This finding suggests that compared to the saving of physical capital, the saving of non-physical capital is influenced more strongly by institutional quality.