The main way of measuring poverty is to set a poverty line and then determine how many people fall below this line.
While related, the attempt to measure poverty in general is a very different undertaking from the effort to measure a specific underclass.
This is the problem in developed countries when it comes to measuring poverty.
Governments routinely measure poverty, but finding the most appropriate standard is difficult and controversial.
Other nations, like the United States, measure absolute poverty - based on the costs of essential items like food and housing.
Deaton has also developed the benchmark methodology for measuring poverty.
But measuring poverty is difficult for a particular country, let alone the world.
Despite the widespread use of the World Bank's standard, there are deep divisions over how to measure poverty.
Even if everyone could agree on just how to measure poverty, some experts argue that the entire idea of using a threshold is misplaced.
In order to measure and quantify poverty, we need precisely defined indicators.