This section introduces the primary measure of poverty in a population and reviews the basic statistical concepts relevant to its estimation.

Poverty is defined as the shortage of essentials for everyday life of an individual or a household. The acquisition of many of these essentials, though not of all of them, is mediated by money-by paying for goods and services. That is why poverty is commonly interpreted as shortage of financial resources. Health care, education, clean environment, transportation, telecommunications, legal services, political representation, personal safety and security, and the like, are other essentials. Where they are provided universally with no barriers to access, their availability is taken for granted, and financial poverty is then rightly the principal concern. In everyday discourse, we qualify the term ‘poverty’ according to its various aspects, including severity (e.g., as absent, mild, moderate, severe or extreme). Yet, when we turn to its more profound characterisation as a social phenomenon ubiquitous in most countries and their regions, we often opt to describe an individual or a household by a dichotomy, as either poor or not poor, which is too coarse for many purposes.