Chinese population prospects projection]

Production of population and goods are closely related, mutually restricted, and should be included in our economic plan. Population projection is important in implementation and study of population policy. It is also the foundation of population regulations. Assuming 2 children per couple the population growth rate will be 1% in 1985 and .6% in the year 2000. Therefore, we cannot realize our goal of .5% population growth rate by 1985 and 0% by 2000. A 9% annual growth rate of national production will be required to reach our goal of $1000 U.S. per capita income by the year 2000, a goal that history proves is difficult to achieve. 2 children per couple, therefore, cannot meet our urgent requirements of modernization and educational improvement. A 2nd assumption of 90% single child families after 1 year would yield an average annual population growth rate of .38% in 1985 and .012% in the year 2000. This assumption leads to a rapid population decrease, too rapid for most to accept the change. The 3rd assumption is a gradual increase in single child families to 50% in 1985 and 90% in the year 2000. The resulting growth rates will be .5% in 1983 and near 0% in the year 2000. The projected population boom from 1987 to 1996 will be decreased to an annual increase of .4-.5%. This assumption provides time for people to understand and recognize the importance of the policy. It meets the requirements of modernization and will help improve China's educational and living standards. All 3 assumptions were based on 3 children per couple for minorities.     

Fertility model and population projection]

Different models for projecting fertility rates for the projection of population, are discussed. It is suggested that the age span cumulative fertility rate (ASCFR) can replace the traditional age span fertility rate because the former is more accurate. A gradual decrease from the highest childbearing age (49) to lower ages will yield fertility rates at all ages based on the ASCFR curve.     

Some fundamental problems in population projection]

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.     

Six microcomputer programs for population projection: an evaluation

Microcomputer-based population projection software packages were evaluated to determine if all the programs would yield similar results if tested on the same set of data. These included the PROJ5 from Microcomputer Program for Demographic Analysis, converted for microcomputers by Westinghouse; the FIVFIV/SINSIN from The Population Council; the PROJPC-II, developed by Kenneth Hill for the World Bank; and CELADE, developed by Centro Latinamericano de Demographia (CELADE), a Spanish microcomputer version of the population projection program of the United Nations. These were all modified from mainframe programs. The DEMPROJ, developed by the RAPID2 project at the The Futures Group, and ESCAP/POP, developed by the Population Division of the U.N. Economic and Social Commission for Asia and the Pacific (ESCAP) were both specifically developed for microcomputers. A standard set of criteria covering hardware and software and requirements, methodology, projection results, and summary demographic indicators in the output are used in the evaluation. Table 1 gives hardware and software requirements. All the programs can be used on IBM or compatable micros. Table 2 gives data input requirements, which vary widely. All 6 programs use a cohort-component projection, although there is a wide variety in application of methodology. Programs and data sets produced similar results, and choice of a system should based on intended use. Appendices list programs and addresses for obtaining copies as well as other kinds of software available for demogrphic analysis and their sources.     

The stochastic inverse projection and the population of Velletri (1590-1870)

A new stochastic method of inverse projection based on the simulation of age and sex of deaths is proposed. The method is implemented in two procedures, i.e., SIPAV (forward inverse projection) and SIPIN (backward inverse projection). The two procedures are used to study the history of the population of Velletri from 1590 to 1870.     

A projection of the population of three counties in Zhejiang Province]

This report is based upon information on population statistics and death statistics by different age groups in Yuyao, Jiangshan, and Huangyan counties of Zhejiang Province since 1978. The population condition in this area is analyzed. Collected information is then used as a foundation for predicting the trends in population growth in the next 20-60 years. In addition, the changes in the population's age structure and their impact are also studied in order to provide useful reference materials for the formulation of reasonable population planning measures. According to the general trends of population growth as predicted in this report, the authors believe that efforts should be made to encourage all married couples to have only one child. The first goal should be that at least half of the married couples have only one childs, and that all parents agree not to have a third child. This basic approach is reasonable and realistic and should not be used as a guiding principle to formulate policies and regulations on population planning. More actions and practices are needed to determine how effective this guiding principle is in reality.     

The exponential multidimensional demographic projection model

"This paper presents the multidimensional demographic projection on the basis of an exponential specification, which avoids the problems associated with the widely used specification on the basis of the linear integration hypothesis. It generalizes earlier work by Gill (1986) on Markov models for closed populations to include the case of open populations. A numerical illustration is also provided." (SUMMARY IN FRE)     

The exponential multidimensional demographic projection model

This paper presents the multidimensional demographic projection on the basis of an exponential specification, which avoids the problems associated with the widely used specification on the basis of the linear integration hypothesis. It generalizes earlier work by Gill (1986) on Markov models for closed populations to include the case of open populations. A numerical illustration is also provided.     

Estimation of local demographic variation in a flexible framework for population projections

A cohort component projection of local populations based on sex and single year of age offers great value for planning local services, but demands data beyond the detail available. Local fertility, mortality and migration schedules by age and sex must be estimated sensitively to local variation if the results are to be of greater value than simpler methods of projection. Two approaches are compared, using data for the recent past: (a) direct estimation of local area age-specific schedules of fertility, mortality and migration based on data available to the national statistical agency; (b) graduation of national schedules using only local area population estimates by age, total numbers of births, and total numbers of deaths; age-specific migration is indirectly estimated from successive population estimates. These two approaches are compared with a projection using the same rates for each area. The three projections have been implemented for electoral wards in the Fife local government area of Scotland, using the flexible framework provided by POPGROUP software. Persuasive local population projections based on standard data for standard areas are feasible without the regular publication of migration flows.     

Voodoo forecasting: Technical,political and ethical issues regarding the projection of local population growth

The case of an energy production community in Colorado is used to illustrate a) the great need for reliable subnational population forecasts, especially in communities expecting rapid population growth, and b) why such projections, as currently performed, cannot be reliable. Explanations for failure in forecasting are found in the methods themselves, the unavailability and unreliability of key data, politics, and the intrusion of the designers' and users' values into the forecasting models. As one solution it is proposed that forecasting be reconceptualized from a technical to an ethical issue and that it be based upon an active rather than a passive planning/forecasting philosophy. As such, the community and industry would set a desired, realistic goal, and forecasting models would be run backwards to determine the economic-demographic paths by which this goal could be achieved.     

An index of the quality of life for victorian children and youth,the vicy index

The range of life-styles of children in nineteenth century Britain is discussed. Concepts of quality-of-life are reviewed and a model for nineteenth century children is formulated. Annual data in three domains are indexed to 1914. Sub-indexes for these domains and a total index are presented and compared with the full index.     

The population of Libya

Very little information is available about the size and composition of the population of Libya. The author has collected together the available information, both official and unofficial. He describes the resources available for feeding the population, and tries to evaluate a natural rate of increase. He reaches the conclusion that the rate of increase is large in relation to the resources that are available and that there is a danger of over-population. An attempt is also made to assess the significance of Italian colonization on the demographic situation of Libya.     

The notion of population economics

Economic literature has not adequately addressed population problems and growth models have assumed the population growth rate as an exogenous constant. Life expectancy and the quality of documentation over a long period have corrected the problem of nonstationary population, however. In addition, mathematical and computational possibilities have been increased thereby allowing population issues to be considered endogenous and variable in models. Recognizing that population changes affect supply and demand and should be studied, a group of economists have found a society to address such population problems--the European Society for Population Economics. Within the realm of population economics are subfields that should be included in any studies. For example, economists must examine household behavior and its influence on having or not having children. Another subfield includes studying the effects of changes in birth rates. For example, birth rates affect age distribution and each age distribution has a typical distribution of demand. A young society would demand schooling and child care, while an old society would need elderly care and health facilities. To enhance optimum population growth, policy makers have several options. For example, family allowances and child care influence procreation, but they require an increase in state expenditures and taxes. Providing health care for all members of society improves the quality of the population and its size. Implementing a migration policy also increases the population. Education and retraining strengthens the quality of the labor force, but some argue that it does not lead to procreation.     

The population policy of China

Summary China has a consistent and well-defined policy to regulate the growth of her population. Population policy is considered as an integral part of overall social and economic development policy. It promotes the reduction of the growth rate in densely populated areas but encourages the increase of population in sparsely populated areas and among national minorities. A series of planned internal migration policies has regulated the spatial distribution of population. Main factors affecting the implementation of China's population policy are the establishment of an effective organization and communication system, the participation of the masses in the work, the socialist transformation of the national economy, the changes in the structure and functions of the Chinese family, the changing status of Chinese women, the development of public health services and the campaign for late marriage and family planning.     

The population biology of coevolution

New populational approaches to the study of coevolution among species are confronting two major problems: the geographic scale at which coevolution proceeds, and the long-standing issue of how species may coevolve with more than one other species. By incorporating the ecological structure of life histories and populations into analyses of the coevolutionary process, these studies are indicating that coevolutionary change is much more ecologically dynamic than indicated by earlier work. Rather than simply a slow, stately process shaping species over long periods of time, parts of the coevolutionary process may proceed rapidly (sometimes observable in less than a decade), continually molding and remolding populations and communities locally and over broad geographic scales.