Japan's history of resident-led assessment shows how local values, collective learning and expert collaboration can generate alternatives and inform public decisions.
Resident-led assessment is a practice in which residents lead inquiry, investigation and evaluation. This presentation traces its history in Japan from the 1960s to the 2020s to identify lessons for future impact assessment.
Using historical documents and practice records, it compares residents' questions, knowledge, alternatives and links to decision-making in three cases. In Nishinomiya in the early 1960s, opponents of an industrial complex proposed an alternative urban vision. A change in municipal leadership rooted in the movement helped translate it into the city's 1963 declaration promoting education, culture and residential life. At Fujimae tidal flat in Nagoya in the 1990s, residents' investigations interacted with scientific expertise and international advocacy, contributing to the landfill plan's cancellation in 1999 and a shift towards waste reduction. In the 2020s, a citizen network assessed the sustainability of Expo 2025 Osaka, Kansai.
Across these cases, residents turned local concerns into assessment questions, shared knowledge through investigation and learning, and proposed alternatives for their communities. This history highlights assessment rooted in local values, collective learning and collaboration with experts. Its influence on public decisions, however, varied across cases.
Future impact assessment should support residents as producers of questions, knowledge and alternatives, and establish mechanisms linking their work to decision-making.
Hiroo Kasagi supports residents’ movements and chairs the Information Committee of the Japan Society for Impact Assessment. He received the Society’s Award for Excellence in 2025.