Progress of G20 Nations on the 6th Sustainable Development Goal Under the Circular Economy Perspective

Clean water and sanitation are essential for public health, economic development, and environmental preservation, underscoring the importance of achieving the 6th Sustainable Development Goal (SDG). Evaluating the progress of G20 nations towards this goal from a circular economy (CE) perspective provides critical insights into the efficiency and productivity of different countries in sustainable water management. This study aims to assess the efficiency and productivity of G20 countries in advancing towards the 6th SDG from a circular economy perspective between 2010 and 2019. We hypothesize that adopting circular economy practices can enhance the efficiency and productivity of countries in achieving the 6th SDG. This study employs data envelopment analysis-slack-based measure (DEA-SBM) to determine efficiency and the Malmquist Productivity Index (MPI) to measure productivity over time. Inputs considered were the population using at least essential drinking water services and renewable internal freshwater resources per capita, while outputs included wastewater treatment and water stress levels. The findings revealed heterogeneous performance between developed and emerging countries concerning progress towards the 6th SDG during the specified period. Efficient developed countries included Germany, Australia, and the UK, while efficient emerging nations were Saudi Arabia, Brazil, South Africa, and India. The results suggest that all countries, regardless of their current performance, have significant potential to enhance their efficiency by devising strategies aligned with sustainable development and environmental policies that resonate with CE principles. This potential for improvement should make all stakeholders feel included and part of the solution. Moreover, productivity gains were predominantly driven by efficiency improvements rather than technological advancements, highlighting the need to prioritize research and development of resource-efficient technologies to expedite the achievement of the 6th SDG. In the short term, a collaborative and multilateral effort is crucial, involving financial assistance, technology transfer, training, capacity building, public–private partnerships, policy development, awareness campaigns, and disaster and crisis response from developed to emerging countries. This emphasis on collaboration should make all stakeholders feel the importance of their involvement. Such efforts could significantly improve access, innovation, efficiency, community awareness, and health and well-being, advancing progress towards the sixth SDG.