Trade-offs in impact assessment design and implementation

Trade-off choices frequently stir controversy and conflict in Impact Assessment (IA). Policy-makers, theorists, and practitioners have long been recognizing the importance of trade-offs, but most practical attention and work has centred on mitigating the adverse effects of assessed projects and other undertakings. In the coming years, responding to climate change and other growing sustainability challenges will require assessments and trade-off evaluations to go well beyond mitigation of adverse effects. This chapter, based on an integrative literature review and taking into account the historical background for trade-off choices, identifies a wide range of trade-off choices involved in IA, and considers how trade-off deliberations and decision-making over IA regime design and application can be adjusted to address the growing needs and expectations of society. It highlights the importance of decision-making centred on the public interest, as well as of sound assessment criteria, trade-off rules and specific guidance for the many challenges associated with trade-off choices and evaluations.