We live in an age of increasingly abundant statistical information. The advent of more large data sets obtained from household surveys, as well as from population censuses, labour force surveys, economic censuses and so on, has facilitated reasonably accurate estimates of income and expenditures for households in many parts of the world. These estimates can in turn be used to estimate a number of distributional indicators, as well as estimates of relative and absolute poverty. In addition better census coverage has permitted estimates of infant and child mortality rates, life expectancies, literacy rates and indicators of educational attainment. Such data have in turn been used to estimate composite indicators of wellbeing such as the Human Development Index, not just for entire countries but often for regions within countries as well.