Brundtland Commission (1987)
"..development that meets the needs of the present without compromising the ability of future generations to meet their own needs"
Norton (2005)
Weak
based on human welfare measures
all forms of capital are convertable (built, human, financial, natural)
there can be one aggregated index of development
fits with neo-classical economics
Strong
pluralistic definition that counts "stuff" and "welfare"
some forms of capital, such as natural capital, are a specially protected class of assets
Brundtland Commission. (1987) Our Common Future. World Commission on the Environment and Development.
Norton, B. G. (2005). Sustainability: A philosophy of adaptive ecosystem management.
Chicago, University of Chicago Press.