What do we mean when we say someone is living in poverty? Do we mean that their income is too low, that their consumption is too low, or that given their particular level of either, their ability to participate in society is severely restricted? Once a poverty line is set, other questions arise. Should our focus be on individuals or families? ‘Measurement’ considers different measures of well-being and explains the differences between absolute and relative concepts of poverty. For public policy purposes, we need simple statistics that summarize the state of affairs overall. Only by tracking such statistics over time can we determine whether our efforts to reduce poverty are paying dividends.