‘Leave no one behind’ has become an important principle of the entire 2030 Sustainable
Development Agenda and the Sustainable Development Goals that brings inequality to the
centre stage. Although a precise definition of what it is to lag behind is essential to assess
sustainable economic growth and social progress a discussion on the desirable properties of
such a measure is absent in the literature. This paper fills that gap by proposing and discussing
a number of normative and analytical properties a measure of the `Leave no one behind´
principle should satisfy. The axioms proposed are necessary and sufficient to characterize
the fuzzy measure by Garcia-Pardo et al. (2021) and together with other additional axioms
make the structure of this measure more transparent.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech