Sustainability as Justice: Making the “Leave No One Behind” Work

This paper critically engages with the LNOB principle of the 2030 Agenda, highlighting its conceptual, methodological, and structural limitations. Building on Amartya Sen's social choice theory and Rawlsian justice, it reconceptualizes “sustainability as justice,” emphasizing real‐world comparative assessments grounded in intersectionality. It develops a novel methodological framework combining the CART algorithm and its descriptive and statistical outputs with the D‐index to systematically identify, measure and assess exclusion across plural informational spaces—resources, capabilities, rights and liberties, and subjective well‐being. Applying this framework to MICS data across nine countries, the paper reveals how conventional SDG disaggregation masks structural inequalities and fails to capture the realities of the worst‐off groups. Instead, it uncovers context‐specific patterns of deprivation and prioritization, offering targeted, empirically grounded insights for policy reforms. Ultimately, this approach reorients LNOB from an aspirational slogan to a justice‐centered, operational tool capable of diagnosing and addressing systemic disadvantage in sustainable development.