Population ageing

Population ageing is a phenomenon that occurs when the median age of a country or region rises due to rising life expectancy and/or declining fertility rates. There has been, initially in the more economically developed countries (MEDC) but also more recently in less economically developed countries (LEDC), an increase in life expectancy which causes the ageing of populations. This is the case for every country in the world except the 18 countries designated as "demographic outliers" by the UN. For the entirety of recorded human history, the world has never seen as aged a population as currently exists globally. The UN predicts the rate of population ageing in the 21st century will exceed that of the previous century. Countries vary significantly in terms of the degree, and the pace, of these changes, and the UN expects populations that began ageing later to have less time to adapt to the many implications of these changes.

Overview

Population aging is a shift in the distribution of a country's population towards older ages. This is usually reflected in an increase in the population's mean and median ages, a decline in the proportion of the population composed of children, and a rise in the proportion of the population that is elderly. Population ageing is widespread across the world. It is most advanced in the most highly developed countries, but it is growing faster in less developed regions, which means that older persons will be increasingly concentrated in the less developed regions of the world. The Oxford Institute of Population Ageing, however, concluded that population ageing has slowed considerably in Europe and will have the greatest future impact in Asia, especially as Asia is in stage five of the demographic transition model.