Evolution or revolution? Reflecting on IA effectiveness in Thailand

This paper investigates whether the Thai impact assessment (IA) system should develop through revolution or evolution. A timeline of the Thai IA system is mapped to show its development to date. Aspects of effectiveness (i.e. procedural, substantive, transactive, and legitimacy) are then used as the benchmark against which to evaluate past IA practice in terms of strengths, limitations and challenges. IA practice is analysed both in terms of the people within the IA system and the IA system itself, as both are considered key elements in making IA work. The findings suggest that the ongoing evolution of the IA system has continued to improve its procedural, substantive and transactive effectiveness; therefore, suggesting that continuing evolution is sufficient to deliver these dimensions of effectiveness. However, the findings also indicate that it is the people in the IA system that influence practice and arbitrate legitimacy. Developing the system over time has not significantly improved legitimacy, leading to the conclusion that gaining legitimacy in the IA process might need some elements of revolution.