For reasons of space and coherence, we decided to omit several topics that might have been included
within a broader definition of sustainability. These topics include sustainable production within
specific resource sectors (agriculture, forestry, and so on); macroeconomic “sustainable growth
models” with no environmental components, which include most of the mainstream endogenous
growth literature; the practical and philosophical impact of population growth on sustainability;
purely ecological models of sustainability; methods and practices for accounting for “green” income;
and studies of economic growth and the environment.