Below-Median Development Indicators: Case Study of Human Development Index

Abstract Striving for inclusive development requires looking beyond national averages to the outcomes of those who are being left behind. This paper introduces a flexible class of below-median development indicators and demonstrates the idea with the Human Development Index (HDI). We re-engineer the HDI into a Below-median Human Development Index (BHDI), computing bottom-half (BHDI-50) and bottom-quartile (BHDI-25) scores for 117 countries. The new index re-weights the HDI’s health, education, and income pillars toward the lower tail of each distribution, producing an intuitive measure that aligns with the Sustainable Development Goals and the World Bank’s shared prosperity target. Average losses equal 24% for the bottom half of the population and 41% for the bottom quartile. Countries with lower HDI levels experience larger losses, implying higher inequalities, while several high-HDI countries drop a development category when ranked by BHDI. The bottom-quartile BHDI offers a simpler and more transparent alternative to the Inequality-adjusted HDI—or a deliberately pro-poor complement to the original HDI. Because the framework is modular—cut-offs and indicators can be swapped—it can be extended to other multidimensional indices or applied to specific population groups, giving policymakers a concise equity dashboard for targeting inclusive development.