Projects should have a realistic theory of change, and the CBA and evaluation should align with the project design and logic. The original design and project logic of the works in Tanzania posited that the higher level results of the project would be decreased mortality and increased economic activity. The CBA also posited a decrease in stunting. While the project clearly increased the water available in the system, the pathways to these higher level results were not well-articulated and potentially not well-founded, particularly since the project only addressed rehabilitation of the water treatment plant and did not address broader network and connectivity issues or household water storage and treatment. In addition, the project was never designed to ensure continuous water supply in the system. As such, better water quality that was consistent enough to lower disease rates was not a realistic benefit. This misalignment between the interventions being designed and implemented (i.e. more water, but not enough for continuous supply in the system) and the likelihood of anticipated results (i.e. better health outcomes) led to challenges in designing the evaluation and some misalignment between the evaluation measures and the benefits modeled in the CBA. MCC now is developing stronger linkages between economic analysis tools such as the CBA and the evaluation questions to address some of these gaps.
Lesson Learned