This model represents the population of ancient Rome in 200 BC with a density-dependent birth rate...the birth rate does not equal the death rate when the population is at carrying capacity because immigration and emigration are also factors. All values are based on historical estimates, as precise figures are not available.
Carrying capacity becomes less effective at maintaining a population when outsiders can migrate in and out. Even though the birth rate may be slightly negative, immigration can lead to a booming population increase
The Model is for an increase in population growth and can not represent a decrease. The time frame is 300 years rather than 100, as it provides a clearer picture of where the long-term growth is heading
