Monitoring inequality in water access: Challenges for the 2030 Agenda for Sustainable Development.

The diffusion of the indicators for monitoring sustainable development goals (SDG) has conceptual and symbolic uses far beyond their instrumental uses. Despite its value in dismantling social and economic inequalities, the goal regarding guaranteed of water and sanitation for all did not specify any indicators for this purpose. This research contributes to the discussions on the best way to monitor inequality in access to water by the SDG. Inequality measures established in other areas of study and specific to the access to water were analyzed as their applicability for this purpose. Our study finds that current United Nations strategy does not allow for robust conclusions and does not respect some economical axioms. Furthermore, we show the potentialities and inconveniences of the most important metrics, but it can be concluded that if the objective is merely to measure inequality and communicate easily, the concentration index is the most appropriate measure. These results may contribute to a more refined discussion of how the SDGs can measures progress towards equality in water access and provides information to guide governments agendas for equality in water access.