Table 1.
Summary of scenario assumptions for indicators of model variables
| Model variables and indicators | Business as usual (BAU) | Open economies | Closed economies | |
|---|---|---|---|---|
| Population | Age distribution, by sex | UN 2015 base year | UN 2015 base year | UN 2015 base year |
| Migration | Net numbers of migrants, by sex | UN medium variant net migration numbers (negative for all four countries) | 2015–2020 = 1.25 × average BAU level 2020–2025 = changes to average BAU level 2025–2030 = changes to zero by 2030 2030–2050 = changes to highest recorded net migration number, (+) sign is substituted for (−) if highest number is negative (−) |
2015–2025 = average BAU level 2025–50 = changes to highest recorded negative net migration number |
| Modes of change | Linear | Linear, constant | ||
| Age pattern of migration, by sex | Model Western Standard UN (1992)a | Model Western Standard UN (1992) | Model Western Standard UN (1992) | |
| Fertility | Total fertility rate (TFR) | TFR 2015 level changes to 2.1 by 2050 | TFR 2015 level changes to 1.5 by 2050 | TFR 2015 level changes to 2.4 by 2050 |
| Mode of TFR change | Linear | Linear | Linear | |
| Age pattern of fertility | UN medium variant | UN medium variant | UN medium variant | |
| Mortality | Life expectancy at Birth e(0), by sex | 0.1250 life expectancy years increase per calendar year | 0.1875 life expectancy years increase per calendar year | 0.0625 life expectancy years increase per calendar year |
| Mode of e(0) change | Linear | Linear | Linear | |
| Age pattern of mortality, by sex | Constant WHO 2008 age pattern of mortality estimate by country | Constant WHO 2008 age pattern of mortality estimate by country | Constant WHO 2008 age pattern of mortality estimate by country | |
| Economic production | GDP | 2015–2035 = average annual GDP growth rate 2000–2015 | 2015–2035 = 1.25 times BAU scenario | 2015–2035 = 0.5 times BAU scenario |
| Workers productivity | GDP/W | 2015–2035 = average annual GDP/W growth rate 2000–2015 | 2015–2035 = 1.25 times BAU scenario Morocco (Morocco, Algeria), 1.5 times BAU scenario (Tunisia, Turkey) | 2015–2035 = no increase, no decrease |
aUnited Nations (UN) (1992), Preparing migration data for subnational population projections, pp. 41–44. New York. 1992