“…To the extent that such operations can have the effect of preserving or building required levels of such capital, we can say that they are sustainable; if they have the opposite effect, we can say that they are unsustainable. This is the capitals-based theory of sustainability performance, and we subscribe to it (Chambers et al, 2000;Daly, 1996;Elkington, 1998;Georgescu-Roegen, 1971;Hawken et al, 1999;McElroy • Human capital. Human capital consists of individual knowledge, skills, experience, health and ethical entitlements that enhance the potential for effective individual action (Becker, 1964;Mincer, 1958;Schultz, 1961).…”