Population growth

Population for the scenario years is calculated with the following formula:

Pn = Pb * (1+ G/100)N + M

with

Pn = new Population
Pb = Population of previous time step
G = Annual Growth rate in %
N = Timestep, usually 5 (years)
M = Migration (in absolute numbers)

The previously applied formula

Pn = Pb * eG/100 *N + M

proved as being mathematically wrong and has been discarded.

The annual results of the population forecasts are stored in table STP_POPULATION.


Notes on Parameters:

Timestep N. Usually 5 years except for 2005. For that year, N is the difference between 2005 and the reference year for which billing data are applied.

Migration is the assumed total migration in or out of the selected DCs between the years for which demands are to be calculated. Since the time between the balancing years is of no interest, it is sufficient to enter M only for the balancing years. Usually Migration does not apply to a large selection of Demand Centers!

The general concept of growthrate and migration is widely applied in the pre-processing module.