The Role of Homogeneity and Heterogeneity Among Resource Users on Water Governance: Lessons Learnt from an Economic Field Experiment on Irrigation in Uzbekistan

The governance of common-pool resources, such as irrigation systems, is a highly debated topic in research. Numerous studies suggest that actors can successfully manage these resources through cooperation, especially in hybrid governance structures, if they are able to design and enforce their own rules. Thereby, certain factors, such as the composition of a group of resource users, influence the likelihood of cooperation and the performance of self-managed resource systems. This study employed an economic framed field experiment to compare the effects of externally imposed and self-set rules of water distribution on homogeneous and heterogeneous groups of irrigation users who differ in their economic endowment. The experiment was conducted with 20 farmers in an Uzbek community. Furthermore, questionnaires, group discussions and interviews complemented the analytical method. The results show that groups, homogeneous in their economic endowment are more inclined to comply with self-designed rules than groups that are economically heterogeneous. Thus, homogenous groups achieve a better performance in terms of resource maintenance and water harvest under self-governance. However, water distribution was more equal and the illegal activities decreased in both the homogeneous and heterogeneous groups with self-implemented rules. It was found that trust was a crucial factor regarding both greater individual rule adherence and more cooperative behavior within homogeneous entities compared to heterogeneous groups of irrigation users. Finally, the results support the argument that economic heterogeneity among resource users lowers the likeliness of cooperation in self-governed common-pool resource systems.