Some older groupings ( `` high/medium/low income countries '' ) that were based on the gross domestic product ( GDP ) in purchasing power parity ( PPP ) per capita have been replaced by another index based on the gross national income ( GNI ) in purchasing power parity per capita .
Some older groupings ( `` high/medium/low income countries '' ) that have been removed were based on the gross domestic product ( GDP ) in purchasing power parity ( PPP ) per capita , and have been replaced by another index based on the gross national income ( GNI ) in purchasing power parity per capita .