Sustainability in the economic conception is often defined as a constant intertemporal level of welfare (see for example Arrow et al., 2004). Weak sustainability was initially associated mainly with economic growth theory with exhaustible resources but has been applied
in a broader sense (Cabeza Gutés, 1996). In contrast, ecological economics argues for strong sustainability, i.e. non-substitutability of natural and built capital, because as Ayres et al. (2001) state: “it is increasingly clear that the criteria for weak sustainability, based on the
requirements for maintaining economic output, are inconsistent with the conditions nece