3.1 The base population: The projection is based on the Registrar General for Scotland's population estimates for mid-2008. The population covered includes all persons usually resident in Scotland, whatever their nationality. Members of HM and non-UK armed forces stationed in Scotland are included; HM forces stationed outside Scotland are excluded. Students are treated as being resident at their term-time address.
3.2 The assumptions about future patterns in fertility, mortality and migration are based on analysis of past trends. The final decisions on assumptions take into account the views of a range of groups who are consulted including a UK expert advisory panel and key users in Scotland. These consultations discussed the likely impact of, for example, increasing child obesity and the economic downturn.
3.3 Fertility: The fertility rates used in the projection are based on assumptions about the average completed family size of successive cohorts of women. It has been assumed that the average completed family size will continue to decline from around 1.85 children per woman for those born in the early 1960s and now reaching the end of their childbearing lives, before levelling off at 1.70 for those born in the 1990s and later. The number of births is expected to fall from around 60,000 in 2008 to around 53,600 in 2033. More details on the fertility assumptions are available in Annex A.
3.4 Mortality: Future improvements in mortality rates are based on the trend observed in the period 1961 to 2007. It is assumed that reduction in mortality rates will tend towards a common reduction at each age of 1.0 per cent a year by 2033 for most ages and then continue to improve at this constant rate thereafter. Based on these rates, expectations of life at birth are projected to increase from 74.8 in 2007 to 80.7 in 2033 for males; and from 79.8 in 2007 to 85.3 in 2033 for females as shown in Figure 5. More details on the mortality assumptions are available in Annex B.
Figure 5 Expectation of life at birth, Scotland, 1983-2033
1 2008-based projection
3.5 Migration: It is assumed that from 2014-15 onwards there will be a net inflow of 12,000 people per year to the end of the projection period, i.e. the total number of people entering Scotland as migrants is assumed to be 12,000 greater than the number leaving Scotland. This assumption has been derived from analyses of trends in civilian migration to and from the United Kingdom as well as cross-border migration between the four constituent countries. In the first six years of the projection higher net inflows are assumed, reflecting recent trends described in Section 2.4. See Annex C for more details on the migration assumptions.