218 Ralf E. UlRich
7.3.1 Population scenarios
Population projections usually start from assumptions about the future
course of fertility, mortality and migration. The combination of these
assumptions results in scenarios that ref lect a broad spectrum of pos-
sibilities according to the respective hypotheses. The variant chosen by
the experts as having the greatest probability is depicted as the medium
scenario.
The UNPD calculated a total of eight scenarios in their latest study (see
Table 7.7). Five of the scenarios differ in their assumptions about fertility,
ranging from constant fertility at the present rate to low-, high- and (from
the current vantage point, most likely, scenario) medium-level fertility. A
further fertility scenario (instant replacement fertility) shows what would
happen if all countries were to have fertility rates at the replacement level
(2.1 children per woman). In other scenarios, the current level of mortality
is held constant, or alternative assumptions concerning the spread of HIV/
AIDS or the availability of an HIV vaccine are taken into consideration.
The Population Division extrapolates the data from past migration trends
in each country on the basis of expert opinions and presents the insights
gathered in seven scenarios. In a further scenario (‘zero migration’), it is
assumed that all countries have a balanced net migration in the years
2010-2015.
For the purposes of this study we will use the medium-fertility scenario
specif ied by the UNPD for our further demographic analysis. From the
assumptions made for the medium scenario and current population
estimates, the UNPD calculated the population size and structure by the
year 2100.
Table 7.7 Increase in population through to 2030
Population in millions Index 2030 Yearly increase (%)
2010 2020 2030 2010=100 2020 2030
EU -27 500.4 510.9 515. 8 103.1 0.0 - 0.1
MENa 454.5 529.5 594.6 130. 8 1. 3 1.0
Egypt 81.1 94.8 106. 5 131. 3 1.4 1.1
Morocco 32.0 35.1 37. 5 117. 4 1.0 0.6
Turkey 72.8 80.8 86.7 119 .1 0.9 0.6Source: UNPD (2011a)