Can poverty rates from different countries be compared using the PPI?

Yes. When doing so, the international poverty lines ($1.25/day, $2.50/day, etc.) are recommended since these lines were developed by the World Bank precisely to be compared across multiple countries.

However, PPI-calculated poverty rates from different countries are not perfectly comparable. Please consider the following when reviewing data from multiple countries:

  • Different countries measure and/or value expenditure  in slightly different ways, meaning that Country A might consider a person poor compared to the $1.25/day poverty line, while Country B looking at the same individual might conclude the opposite.
  • Some countries adjust the absolute value of poverty lines for regions within the same country. A country could define just one poverty line or it could vary the value by region, as is the case in Zambia, where there are nine values for each poverty line.
  • PPIs are made when data and funding become available, so they are not created at the same point in time (or even within the same year sometimes). Changes in a country’s economy may, over time, affect the results of a country’s PPI.