Comparing Weak and Strong Sustainability On the Basis of Sustainable Development Concept

In the past half century, sustainable development and its policy implications have attracted a number of researchers in recent decades. In this literature, two rival theories are recognizable which are called weak and strong sustainability. These two theories are based on different assumptions, have different policy implications and expectedly lead to different results. Weak sustainability assumes that all different kinds of capital – especially physical and natural capitals – are complete substitutions while according to strong form of sustainability, none of other forms of capital – including physical, human and social- are substitutes for natural capital. This paper, using the most recent natural capital data provided by UN, compares these theories empirically. Using alternative variables for sustainability as dependant variable, we have compared the explanatory significance of different types of capitals in several regression equations. The results show that natural capital significantly explains sustainable development indices. Even, when other forms of capital are included in the regression equation, the positive relation between natural capital and sustainability indices remains statistically significant. So, we can conclude that empirically speaking, as stated in strong sustainability theory, other forms of capital are not substitutes for the natural capital.