Why do the reference years for the surveys used for the MPI differ by country? Isn’t it unfair to compare countries if the statistics in one case are five years older than in another?

The MPI relies on the most recent and reliable data available since 2009. The difference in dates limits direct cross-country comparisons, as circumstances may have improved, or deteriorated, in the intervening years. This is the reason why we do not rank countries based on the MPI value.

Data for the 2021 MPI are from 2009–2020, though 3.9 billion of the 5.9 billion people covered and 1.1 billion people of the 1.3 billion identified as multidimensionally poor (84 percent) are captured by surveys from 2015 or later (79 of the 109 countries covered and 22 of those countries have data fielded in 2019 or later).