The "effective" population will equalize much faster. SK has extremely high longevity, which is a success, but it means that 9 million of those are already de-

The "effective" population will equalize much faster. SK has extremely high longevity, which is a success, but it means that 9 million of those are already de-facto out of the workforce and are a liability, not an (economic or military) asset. North Korea has really low longevity, which is bad, but it means that more of those 25 million are young.