| Abstract: | When family planning work in China developed, during the 1970's, the work of population projection also expanded. Population projections were done for China and its regions beginning in 1974 and remains a relatively new activity. Some question its validity, while others speculate about its methods and beleive only higher mathematics can be used, but this is all due to a lack of understanding of the nature of population forecasting. It is possible to predict population because if a current population situation and its changes are known, population of a particular future period can be projected e.g. for each year that is lived, a person will be 1 year older. And, population changes are primarily based on changes in births and deaths. These changes in turn are influenced by social and economic factors. Population projection is basically a forecasting of a certain period's total population, age and sex structure, the number of births and deaths, and migration. Different methods and formulas can be used to measure different population indicators, but all methods utilize comparisons. There are basically 2 methods for projecting total population: 1) the "direct method" regards total population as a quantity that itself changes and 2) the "separate factor method" breaks down total population into births, deaths, and migration. In the past, population projection has focused on the natural development of population which can be called "uncontrolled" because it makes "passive measurements" of possible population developments. In China, however, population projection is "controlled." Although it too measures future population developments, China's projections are not based on natural developments, but on definite population policies and estimates of results of family planning efforts. |
