SIA in review: setting the agenda for impact assessment in the 21st century

This article reviews the literature and practice of social impact assessment (SIA) to address some of the perennial questions faced by all fields of impact assessment. What scope is there to extend impact assessment beyond individual projects? How might the different branches fit together? What is the relationship between scientific assessments and public participation? It argues that the relative marginalization of SIA has limited the effectiveness and influence of all aspects of impact assessment. However, this marginalization cannot be blamed entirely on the technocratic world views and political agendas of project proponents, governments and scientific agencies. The strength of SIA is undermined also by a failure to resolve fundamental theoretical contradictions concerning the objects and methods of impact assessment, in particular, the contested role of prediction in SIA. While closure on these issues may not be possible, acknowledgement and clarification of them does suggest positive routes forward for impact assessment.