the demographic transition model
The demographic transition model (DTM) shows population change over time, it studies how birth rate and death rate affect the total population of the country.
stage 1 = high dr, high br, steady e.g. tribes
stage 2 = declining dr, low br, very high e.g. Kenya
stage 3 = rapidly falling dr, low br, high e.g. India
stage 4 = low dr, low br , zero e.g. uk
stage 5 = slowly falling dr , low br , negative e.g. japan