Accuracy and uncertainty of the national population projections for the United Kingdom.

This article considers how accurate recent national population projections for the United Kingdom made since 1971 have turned out to be. The overall size of the population has generally been forecast fairly accurately although this often turns out to have been a consequence of compensating errors in the projections of births deaths and migrants. Fertility has tended to be overestimated mortality assumptions have been too pessimistic and net migration into the United Kingdom has consistently been underestimated. However there is evidence that the accuracy at least over the short-term has improved in more recent projections. The article also discusses variant projections the traditional method of illustrating uncertainty in national population projections. (EXCERPT)