How can you calculate Poverty Gap index?

The Poverty Gap Index (PGI) measures the intensity of poverty by calculating the average shortfall of the income of the poor from the poverty line, expressed as a percentage of the poverty line. To calculate it, first determine the total income shortfall for all individuals below the poverty line, then divide this total by the overall population and multiply by the poverty line. The formula is: PGI = (1/N) * Σ((Z - Yi)/Z), where N is the total population, Z is the poverty line, and Yi is the income of each individual below the poverty line. This index provides insight into the depth of poverty in a population.