Thematic Focal Person: Dalkhat Ediev

Overall vision

Population size and its structure impact many parts of the socio-economic, environmental and political systems. The social security system, health care system, food production and distribution, water supply energy production and consumption, and environmental pollution are all strongly affected by population size and structure. In order to project the population size, its age composition, the number of people residing in different countries or regions or belonging to different categories (for example, having different health, educational and marital statuses), we need to apply conventional demographic methods as well as advanced methods that include multi-state and stochastic approaches. We also need to use or develop mathematical and computer models to project components of population growth such as mortality, fertility and migration.  

Population aging, usually defined as a shift of population age composition towards the older ages, is a consequence of lasting decreases in fertility and increases in life expectancy. Population aging is a potential threat to global prosperity. In particular, an increasing old-age dependency ratio is often considered a threat to social security and retirement systems.

Conventional measures of ageing such as median age, old age dependency ratio, or proportion of people 60 or 65 years and older all indicate strong patterns of aging for most OECD and other European countries, as well as for many countries in Asia, such as China.

Although the literature on population aging in developed countries is exploding, concerns are expressed about the challenges to current economic and social arrangements associated with an ever more elderly population as the concepts used in analyzing aging have remained static.

However, recent WIC studies published in Nature and Science have moved beyond these conventional measures to introduce a new concept of ageing. We show that the dynamics of aging, both historically and prospectively looks very different when we consider increasing life expectancies in determining the age thresholds that define who is old. Indeed, in many instances populations thought to be growing older were actually becoming younger, when measured appropriately. Prospectively, the prospects for aging also appear much less alarming for most countries when the new indicators are applied.

Specific work plans for mid-2011 to mid-2013

In the next several years the research of the WIC team “Population Dynamics and Aging” will focus on the following topics:

Conventional and probabilistic population projections for all countries of the world based partly on responses to the global survey of demographers, related to prospects for fertility, mortality and migration. This activity is supported by the ERC Advanced Grant project, “Forecasting societies’ adaptive capacity to climate change.”

Mortality models that generate consistent age-specific mortality patterns in medium and long term mortality projections, taking into account recent decreases in mortality rates in upper age groups.

New measures of disability and aging for most European countries in order to formulate different policy options related to changes in pension age and employment. The influence of migration and labour force participation rates on several measures of dependency (economic, old-age and prospective old-age) will be a focus.

Forecasts of adult disability, particularly a new model of severe disability for countries with intermediate level of mortality and improved models for countries with high life expectancy. This work will be based on European surveys such as Silc and Share. Japanese surveys of disability among old people and DHS survey will also be used.

Other activities and projects may emerge in the future.