The theory of environmental impact assessment: Implicit models of policy making

In spite of its manifest policy importance, environmental impact assessment (EIA) has been the focus of very few explicit attempts at theoretical understanding. Writing; about EIA has been guided by assumptions and models that have been implicitly assumed rather than explicitly and systematically explored, formulated, or articulated. How EIA is understood to work, how much policy significance is attributed to it, and the meaning it has in the politics of the environment is determined largely by which of these implicit models constitutes a frame of reference. As a first step in developing a theory of EIA, we identify six categories of implicit models based on our survey of scholarly and practitioner literature. We locate and specify each of these models in terms of debates over EIA, analysing implications for a theory of EIA, both operational and normative.