The capability approach (CA) pioneered by Amartya Sen and developed by many others has become decisively influential over the last two decades as a normative framework for assessing social arrangements, social justice, equality, and quality of life, as well as for designing policies (Robeyns, 2011). The CA has also been seen as a theory of social justice seeking to reduce social exclusion and inequalities and to enhance global justice. The CA is probably best known for having inspired the creation of the Human Development Index (HDI) in 1990 by the United Nations Development Programme (UNDP) to annually rank countries by level of human development or well-being. This well-known approach has played a key role in advancing alternative ideas about development and welfare, rather than GDP growth. Thus, evaluated in CA theoretical terms, countries like Japan, for example, may not necessarily be judged to be rich, although on paper, by such measures as GDP and per capita GDP they may rank amongst the world's most prosperous nations.