It appears not straightforward, however, to translate the Brundlandt definition of sustainable
development into manageable policy objectives. Economists tend to translate sustainable development
into non-declining per capita wealth while ecologists tend to address the unavoidable biophysical
constraints of human action. In addition, it is clear that social relationships play a fundamental role in
sustainable development. However, this understanding has so far rarely been converted into explicit
social sustainability objectives. Nevertheless, there is a general understanding that an important policy
goal underlying sustainable development is to lengthen the time-horizon of policymakers. The concept
typically refers to the long-term implications of current actions and addresses long-run policy
objectives, while the time-horizon of decision-makers, on the other hand, is typically rather short. In
addition, sustainable development urges the necessity of setting its three dimensions in such a
relationship that they become mutually supporting. In current practice, however, it is difficult to
formulate such ‘win-win’ policies, which promote simultaneously economic, environmental and social
goals. Nonetheless, the concept of sustainable development should force policymakers to take into
account the impact of policies beyond their own narrow area. Policy decisions then will involve
considering trade-offs between the three dimensions. The concept of sustainable development thus
serves as a way to co-ordinate policies (OECD, 2001a).