Population Projections: New Opportunities for Software Development

The major principles of the development of platform independent software for population projections based on WEB technology are discussed, and a prototype WEB-based demographic server is developed. The possibilities of using the WEB approach for broader issues of demographic analysis and training are discussed. The paper was initially presented by the author at the workshop "Rethinking International Population Projections" organized by IIASA (6-8 June 1996 Laxenburg, Austria). Although almost two years have since passed and WEB technology has become much more powerful, some of the ideas discussed in the paper still await implementation

The End of Population Growth in Asia

This paper presents probabilistic population projections for five regions of Asia (South Asia, Central Asia, China region, Pacific OECD and Pacific Asia) and Asia as a whole. Over this century, Asia will experience a very heterogeneous demographic development: Central Asia is still expected to almost double its population and South Asia will become by far the worlds most populous region, rapidly surpassing the China region. Simultaneously, todays Pacific OECD countries are likely to shrink in size and experience extreme population aging. The proportion of the population above age 60 in these countries (with Japan having the greatest weight) is expected to reach an incredible 50 percent of the total population (with the 95 percent uncertainty interval ranging from 35 to 61 percent). The China region will experience a more rapid speed of aging with the proportion above age 60 expected to increase by a factor of four from 10 percent in 2000 to 39 percent in 2100

Derivative-free Gauss-Newton-like Algorithm for Parameter Estimation

This paper develops the idea of parameter estimation using the derivative-free nonlinear least-squares algorithm. The algorithm was found efficient and convenient for many applications

Multi-State Analysis of Family Dynamics in Austria: Scenarios to the Year 2030

The methods of multi-state demography can generally be applied to any process where transitions between states occur in dependence on age and one is ready to make the Markovian assumption that the transition probability depends only on the present state and on age. It turns out that this methodology fits quite well to the complex field of family demography and helps to avoid several pitfalls of other models such as the traditional family lifecycle approach. Aside from the analysis part the multi-state model can also be used to project the future distribution over states under different scenarios. This was done using IIASA's interactive DIALOG program for the case of Austria

"DIAL" - A System for Modeling Multidimensional Demographic Processes

Multistate mathematical demography, much of the development of which took place in IIASA, has proven its usefulness in a broad range of applications including the analysis of migration, marriage, fertility, working life and household dynamics. Among other things the method makes possible the calculation of population projections which are disaggregated by region (marital status, parity, occupation, etc.). This paper serves as a user's guide to a new microcomputer program which greatly facilitates the use of the multistate projection mathematics. A user with access to the appropriate data and modest skills with a computer can explore the future path of a population under a variety of assumptions about the direction of change in key variables. Graphical displays of results, and interactive updating of assumptions, also contribute to the usefulness of the system. The program described here has already been installed and used in a number of research institutes in several countries

Interpreting UN Urbanization Projections Using Multi-state Model

The United Nations provides the most comprehensive and widely used projections of urbanization at the national level, based on a method that projects differences in urban and rural growth rates over time. Taking the case of China as an illustration, we use a multi-state model to explore the implications of this projection for rural-urban migration, its plausibility, and the uncertainty associated with it. We find net that the UN urbanization projection implies a net rural-urban migration path of just over 10 million per year for the next 20 years, followed by a substantial decline over the 2020s. We also find that alternative migration scenarios can produce a wide range of outcomes for urbanization and for the age structures of rural and urban populations, suggesting that urbanization projections that reflect a full range of uncertainty are desirable. Given the range of possible outcomes for rural and urban age structures - some of which are unlikely or infeasible - it appears advisable that urbanization projections should explicitly model these populations and the age structure of migration

Gender Inequality in Survival at Older Ages

Gender gaps are typically measured by subtracting the survival rates for women from that of men. In most countries and at most ages, these gender gaps indicate a survival rate disadvantage for men. This method is not informative because it is unclear whether larger or smaller gaps would be more equitable. Here we reconceptualize the gender gap in survival based on differences from gender-specific best practice rates and express those gender gaps in the metric years of age. If the age-specific survival rates for women in a particular country are farther behind the best-practice survival rates for women than the survival rates for men are behind their best-practice rates, then there is a gender gap to the disadvantage of women. This facilitates the analysis of gender gaps over ages, time periods and countries. We find that there has not generally been a trend toward gender equality in survival when measured relative to gender-specific best practice. In some countries, gender gaps in survival to the disadvantage of women existed in 1960 and have even grown larger over time. In the UK, gender gaps to the disadvantage of men in 1960 evolved into gender gaps to the disadvantage of women by 2010. The methodology employed here can be applied to quantify gender gaps in a variety of variables and help in the formulation of healthcare policies

A unifying framework for the study of population aging

Aging is a complex, multifaceted phenomenon. In this paper, we provide an integrative approach that allows for the study of numerous dimensions of aging within a unified framework. The framework is based on the translation of quantitative measures of people’s characteristics into a new form of age measure, called “alpha-age.” Two individuals who have the same alpha-age have the same level of the characteristic under consideration. Alpha-ages are easy to understand and analyze because they are measured in years, just like chronological age. Indeed, chronological age is just an alpha-age for which the characteristic is the number of years the person has lived. An advantage of using the alpha-age measure is that it allows for the translation of different characteristics into years of age. Expressing multiple characteristics that are otherwise di ffi cult to compare using a common metric makes it possible to conduct comparative analyses that previously were not feasible. We demonstrate the integrative power of alpha-ages through a set of examples in which we present alpha-ages based on remaining life expectancy, five- year survival rates (a rough objective indicator of health), self-reported health, and hand grip strength. We also show how alpha-ages can be used to compute old-age thresholds that vary over time and place, and how alpha-ages can be used to compute intergenerationally equitable normal pension ages. By allowing for the consistent quantitative measurement of multiple aspects of aging, the integrative approach presented here provides us with new insights into the process of population aging

Population Projections for Forty-Four European Countries: The Ongoing Population Ageing

In the current paper we present the population projections for forty-four European countries. The dynamics of migration might prevent some European countries from experiencing population decline in the near future, although fertility has been below replacement for some time. Similarly, the EU-27 population is projected to further increase. Our results confirm that population ageing is underway all around Europe, albeit with clear differences across countries. According to the traditional measures of population age structure, the countries with the oldest populations are expected to be found within the EU. However, these measures do not take into account the longevity change: a man of 65 living in a country with a higher life expectancy might be at a different stage of the life cycle in comparison to a man of 65 living in a country with lower life expectancy. Relying on three alternative measures of age which consider explicitly changes in the remaining life expectancy, we find evidence that ageing will continue, but (1) it might be more severe in some countries where population is shrinking towards older ages but life expectancy is still rather low; (2) it might not be as fast as it appears when not adjusting for the longevity change. As an example, the former Soviet Union states and some countries of the Balkan region show the highest proportion of population with a remaining life expectancy of 15 years or less; in Italy and Germany the prospective median age and the proportion of population with a remaining life expectancy of 15 years or less might increase at a slower pace than the corresponding conventional measures, i.e. the population median age and the proportion of people aged 65+