Thomas Roca (AFD) reports on the state of the ongoing discussions regarding the methodological and conceptual evolutions of the HDI, which took place recently at the Agence Française de Développement, in Paris, on January the 27th and 28th, 2013, and at the UN, New York, on March the 4th and 5th, 2013. The debates focus on the constant tradeoff between advocacy and accuracy, and on entrenching sustainability within HDI.