This paper looks at projections for the Spanish population by sex and age for the
period of 2005 to 2050. These were carried out using forecasts for birth and
mortality rates, and migration. These rates are calculated using two main sources of
information. First, a multivariate time series model was applied for the series of
variables from the 1970 to 2001 period. Second a model was estimated for life
expectancy and for a synthetic fertility index. Both sources of information were
combined to obtain the forecasts for the rates. Immigration rates are predicted by
assuming three possible scenarios based on the maximum proportion that
immigrants will represent in the Spanish population. With these variables a
structure of ages and sex for the Spanish population is estimated using a cohort
component model
