Na tional in come, popu la tion, and ur ban growth rates are also as sumed for each coun try group, along with an tici pated changes in these rates over time. The model uses the re vised United Na tions medium- variant pro jec tions for 1996 for demo graphic as sump- tions. Na tional in come pro jec tions are es ti mated based on a re view of pro jec tions drawn from sources such as the World Bank. The model is solved on an an nual basis by link ing each coun try model to the rest of.
