Validating simulations of development outcomes in the Mekong region

The wider Mekong region is experiencing an unprecedented influx of private and foreign investment, which is transforming many areas of the six riparian countries. Most investments target access to natural resources, demoting the outcomes of development objectives such as poverty alleviation to coincidental side-effects. The Mekong region simulation (Mersim) model aims to improve the understanding of unintended side-effects, by providing the computational foundation for a participatory learning process involving decision makers and decision influencers. The model simulates the poverty and economic outcomes of scenarios selected and designed by participating decision makers, including the impact of Mekong mainstream dams, the impact of payments for ecosystem services on land use change, the impact of large scale irrigation, and the impact of sealevel rise. The complexity of these social-ecological processes emphasises the relevance of iterative participant validation. This paper describes a process that involves a pattern-based validation technique as an alternative to a numerical validation method. The patterns were introduced in structured workshops to challenge causal beliefs elicited during the participatory process and validated through facilitated stakeholder discussions. This paper explains how, as an initial response, stakeholders actively defend currently held beliefs. When confronted with the counterintuitive results and outcomes simulated by the Mersim model, the discussion shifted to understanding model mechanisms, allowing stakeholders to explore alterative beliefs and some held beliefs were readily amended, validating some important results of the Mersim model.