Essential variables help to focus Sustainable Development Goals monitoring

The imperative to measure progress towards Sustainable Development Goals (SDGs) has resulted in a proliferation of targets and indicators fed by an ever-expanding set of observations. This proliferation undermines one principal purpose of the SDGs: to provide a framework for coordinated action across policy domains. Systems approaches to defining Essential Variables have focused monitoring of climate, biodiversity and oceans and offer opportunities to coordinate SDG monitoring. We propose four criteria and a process to identify Essential SDG Variables (ESDGVs), which will highlight interactions and gaps in current monitoring. The ESDGV criteria suggest a research agenda to: develop and test interdisciplinary system models; test transformations theory for sustainable development; analyse policy interactions; and formulate models to support further refinements of ESDGVs and SDG monitoring.