Mesurer le développement : autres données, autres conclusions ?

We now have more and better measures of economic development than ever before. The number and availability of household surveys have been improving over time. These surveys provide data, not only on household incomes and expenditures, but also on direct measures of health, particularly on anthropometrics, on infant and child mortality, as well as on self-reported measures of well-being and emotional experience. It is possible, for the first time, to compile global maps of multiple components of human welfare. The latest round of the International Comparison Project (ICP) has collected prices of comparable items in 146 countries, many of which have not been previously surveyed. These new data have brought many new insights and new discoveries about economic development of both nations and of individuals. Yet there are also problems of interpretation and consistency between the different types of data. Why does world poverty not fall as fast as might be expected given the amount of growth in the world? Why are Indians consuming fewer and fewer calories when their nutritional status is so poor, and their incomes are rapidly rising? Why is economic growth not always associated with improvements in self-reported well-being? And how should we interpret the marked increases in estimates of global poverty and global inequality that came with the latest data from the ICP? This paper reviews these puzzles and questions and identifies key questions that need to be resolved.