It is important to stress that we treat the estimate of life expectancy at birth as a general indicator of the impact of various forces, such as the dissemination of medical knowledge, public health programs to combat the spread of infectious diseases etc., have had on improving health over time or the devastating effect of the HIV/Aids pandemic on the deterioration of health in more recent years. [...] The WDI provide data for the share of income of the middle three quintiles and for the top two and bottom two deciles. [...] The θ are the Lagrangian multipliers of the optimization procedure and can be interpreted as the “shadow value” of the constraints. [...] In addition to measuring the degree of income inequality, estimation of the world distri- bution of income allows measurement of the extent of global poverty. [...] In effect, the joint distribution consists of separate ‘higher’ and ‘lower’ distributions, reflecting the substantial gap in terms of income and health between the developed countries and the rest of world.