Leaving no one behind (LNOB) has been a central overarching concern of the 2030 sustainable development agenda that was passed in 2015 as well as of on-going monitoring activities, including, for example, the 2016 High-Level Political Forum convened by the Economic and Social Council of the UN (ECOSOC). At the same time, there is a lack of clarity what exactly is meant by leaving no one behind, what implications this has for the overall 2030 agenda, and how, for example, difficult trade-offs between the call to leave no one behind and other SDGs can be managed.
This paper provides an overview of these issues and seeks to provide some clarity on the problems involved. After reviewing some existing documents on the topic, it will propose ways to operationalize LNOB, discuss whether to take a country-focused or person-focused approach, examine various (multidimensional) ways to measure those who are left behind, argue in favor of concern for LNOB on intrinsic and instrumental grounds, suggest ways to identify those at risk of being left behind, and discuss difficult trade-offs of an agenda focused on LNOB with other SDGs.
One general conclusion arising from this discussion is that LNOB should be seen more as a way to assess how overall development strategies reach those at risk of being left behind (and what can be done to improve such strategies in LNOB) rather than being an agenda for a multitude of finely targeted (and fragmented) programs to separately address each and every form of disadvantage.