Determining the facts that matter in complex decision-making: A critical realist framework of identifying valid knowledge in planning

While the role of valid knowledge in planning decision-making is recognised in literature, the determination of validity and its relationship to controversial planning decisions is under theorised. In this paper, critical realism is utilised to explore hegemonic influences on the determination of validity as an explanation for controversy and contestation. Findings from a UK case identify a hegemonic lag whereby hegemonic rationalities and doctrines actualise decisions that endure through subsequent planning processes despite political and public contestation, and changes in policy, local context, and planning personnel. This lag narrows the scope of valid knowledge, excludes public input, and directly influences controversy. The paper recommends increased agency for planners to respond to contextual change when (re)determining approval for development. Future research directions in contexts where observed inertia of the planning system is considered alongside political struggle and contestation are suggested.