Inequalities in water, sanitation and hygiene: Challenges and opportunities for measurement and monitoring

While there is significant awareness of the importance of addressing water, sanitation and hygiene (WASH) inequalities, measurement continues to present a challenge. Addressing how inequalities are measured, tracked and communicated is fundamental to accelerating progress in ensuring universal WASH coverage and associated benefits. We review how WASH inequalities have been measured and monitored to date on a global level, particularly in relation to SDG 6. We describe gaps in several areas, including how inequalities are measured in relation to gender and social differences, and limitations due to a focus on measuring access to infrastructure that overlooks other contributions of WASH services to wellbeing. Approaches for improved measurement and monitoring of inequalities are discussed, including making better use of existing datasets, as well as developing a broader range of indicators for the WASH sector. Finally, we emphasize the importance of improving visualization and communication of inequalities to policy audiences.