Abstract: | Abstract Conventions exist for carrying out the arithmetic of population projection, finding the intrinsic rate of natural increase, and other demographic calculations. These are good approximations only for populations which are stationary or increasing very slowly. For rapidly increasing populations, which are presently the subject of much study, they can be readily improved. The improved formulae take account of the way in which the increase shifts the distribution of population within the five-year age group. A number of examples are given of the derivation of corrections to existing formulae. While the corrections are smaller than the error of the data available for most countries, such formulae are worth introducing in anticipation of better data. They in no way depend on machine computation, but the computer makes them especially easy to apply. |