ABSTRACT
An early demographer, Gregory King, writing in 1692 on the future growth of the population of England. That, when the Romans invaded England, 53 years, before our Saviour’s time, the kingdom had about 360,000 people; and, at our Saviour’s birth, about 400,000 people; That, at the Norman Conquest, Anno Christi 1066, the kingdom had somewhat above two millions of people. Rapid changes in life expectancy, provision of international aid and the availability of birth control make forecasting for periods greater than five years difficult. In the longer term, estimates are usually made to cover reasonable extremes of change by presenting three sets of projections – high, central and low. A starting population of known (census) size is defined in terms of its age, and area of residence, and future developments in that population are estimated by consideration of the components of change in the light of current experience.
