An example of a participatory co-model is Garcia Barrios et al’s MESMIS project, which focuses on ecosystem management in rural Latin America. In one iteration of this model, stakeholders from a Mexican river-system were invited to take part in a co-modelling process.
These stakeholders included a maize-farming community from along the river, tourist operators from the nearby lake, and local government officials. Representatives from these three groups joined scientists for a three-stage modelling exercise.
In the first stage of the model, the participants explored the situation of the maize farmers, who were seeking to increase the yield of their land by introducing a new fertiliser. By experimenting with the model, participants discovered the quantities of fertiliser required to sustain the members of this community.
In the second stage of the model, the participants took on the role of the tourist operators on the downstream lake. The model demonstrated the impact of fertilizer run-off on the lake ecosystem, and consequently the value of the land for tourism. By experimenting with the model, the participants explored the safe quantities of fertilizer which could be added to the river system in order to sustain the tourist industry.
In the final stage, the participants took on the role of the local authorities, seeking to balance the demands of the two communities with the complex behaviour of the ecosystem.
The result was a consensus agreement on the best approach to managing the river system for all concerned. As is almost always the case, the consensus was a compromise which did not deliver the optimum results for any single group but the best results that all three could accept.