Which factor is NOT included when calculating population growth rate?

When calculating population growth rate, key factors typically considered are the birth rate, death rate, and the change in size over time, which collectively help to determine how fast a population is increasing or decreasing. The birth rate refers to the number of live births in a given year per thousand people, while the death rate represents the number of deaths in the same period. The change in size over time reflects the net result after accounting for both births and deaths.

Migration patterns, while they can influence population dynamics, are not directly factored into the basic growth rate calculation itself. Instead, migration is typically analyzed separately because it involves the movement of individuals in and out of a population, which impacts total population size but is categorized differently in demographic studies. Thus, while migration can affect the overall population, it is not considered when calculating the intrinsic growth rate of a population.