[Gen]General Assumptions

The forecast assumptions were based on time series analyses of age-specific (and total) fertility; age-specific mortality and life expectancy at birth; and net migration by age and sex, and relative to total population size. In each case, experts were interviewed to see if changes seemed desirable. The role of the experts was advisory. The final assumptions are the responsibility of the forecasting group.


For fertility time series methods and expert judgment gave similar results. Both agreed fairly closely with earlier forecasts of both national statistical agencies and Eurostat. Countries were divided into two main groups with the point forecast for total fertility of either 1.8 or 1.4, in 2050:

1.8: Belgium, Denmark, Finland, France, Iceland, Ireland, Luxembourg, Netherlands, Norway, Sweden, United Kingdom,

1.4: Austria, Germany, Greece, Italy, Spain, Switzerland.

Portugal was assumed to have the value 1.6 in 2050.


Statistical estimates of past rates of decline of age-specific mortality indicated a faster decline than that assumed by national statistical agencies or Eurostat in the past. Direct statistical analyses of life expectancy implied a faster improvement than analyses of age-specific rates. Expert judgment agreed broadly with the former but suggested that even faster improvements in life expectancy are possible. In addition, two things were noted: (1) in the past mortality forecasts have usually underestimated future rates of decline, (2) in countries with an exceptionally fast rate of decline in the past the rate of decline would be expected to slow down somewhat, and in countries with an exceptionally slow rate of decline the rate would be expected to pick up (regression to the mean). Based on these considerations, the forecasts were based on past rates of decline of age-specific mortality in such a way that the rate of decline begins from its current level and converges to the average European rate of decline in two decades. In some coutries this would have lead to a divergence of female and male life expectancies, thus reversing the trend of the past two or three decades. A further proportional adjustment to male mortality was made so that female life expectancy would be 4 years higher in 2049 than male life expectancy. In the case of Ireland the gap was left at 5 years due to strongly diverging current trends.

Net Migration

Statistical estimates of the past development of net migration indicated that in most of the countries in-migration had systematically increased during the past 50 years. Continuing the trend would lead to levels of migration that are radically different for most countries from what has ever been observed in Europe. Even maintaining the levels observed in the recent past are higher than the assumptions used by national statistical agencies or Eurostat. However, as in the case of mortality, the latter forecasts have usually been too low. Expert judgment also indicated that the average level observed in the past is more credible than the past forecasts. A regression to the mean is a possibility here, as well. Or, countries with an exceptionally high level of net migration compared to population size would be expected to have a somewhat lower level in the future, and countries with an exceptionally low level of net migration would be expected to have a somewhat higher level in the future. The countries were judgmentally divided into the following groups, by the ratio of total net migration in 2050 and the population in 2000 in 1000's):

1.5: Finland, Iceland, France

2.0: Belgium, Denmark


3.0: Sweden, Netherlands

3.5: Austria, Germany, Ireland, Norway, Switzerland, United Kingdom


4.5: Greece, Italy, Portugal, Spain



6.0: Luxembourg

Last updated 1.10.2004