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Economic &
Social Affairs

2015

World
Population
Ageing

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United Nations

[report]
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Department of Economic and Social Affairs
Population Division

# World Population Ageing
2015

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United Nations • New York, 2015
The Department of Economic and Social Affairs of the United Nations Secretariat is a vital interface between global policies in the economic, social and environmental spheres and national action. The Department works in three main interlinked areas: (i) it compiles, generates and analyses a wide range of economic, social and environmental data and information on which States Members of the United Nations draw to review common problems and take stock of policy options; (ii) it facilitates the negotiations of Member States in many intergovernmental bodies on joint courses of action to address ongoing or emerging global challenges; and (iii) it advises interested Governments on the ways and means of translating policy frameworks developed in United Nations conferences and summits into programmes at the country level and, through technical assistance, helps build national capacities.

The Population Division of the Department of Economic and Social Affairs provides the international community with timely and accessible population data and analysis of population trends and development outcomes for all countries and areas of the world. To this end, the Division undertakes regular studies of population size and characteristics and of all three components of population change (fertility, mortality and migration). Founded in 1946, the Population Division provides substantive support on population and development issues to the United Nations General Assembly, the Economic and Social Council and the Commission on Population and Development. It also leads or participates in various interagency coordination mechanisms of the United Nations system. The work of the Division also contributes to strengthening the capacity of Member States to monitor population trends and to address current and emerging population issues.

## Notes

The designations employed in this report and the material presented in it do not imply the expression of any opinions whatsoever on the part of the Secretariat of the United Nations concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries.

This report is available in electronic format on the Division's website at www.unpopulation.org. For further information about this report, please contact the Office of the Director, Population Division, Department of Economic and Social Affairs, United Nations, New York, 10017, USA, by Fax: 1 212 963 2147 or by e-mail at population@un.org.

**Suggested citation:**

United Nations, Department of Economic and Social Affairs, Population Division (2015). *World Population Ageing 2015* (ST/ESA/SER.A/390).

Official symbols of United Nations documents are composed of capital letters combined with numbers, as illustrated in the above citation.

Cover photo: "Streets of Dhaka: Taming the Future" by Inkiad Hasin, 2011

(https://flickr.com/photos/ragefeast/6117446784/), used under CC BY 2.0, cropped from original

Published by the United Nations

Copyright © United Nations, 2015

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# Preface

In the area of population ageing, the Population Division of the Department of Economic and Social Affairs of the United Nations Secretariat prepares national, regional and global estimates and projections of older populations, monitors levels and trends in population ageing and collects and analyses information on the relationship between population ageing and development. The Population Division also organizes expert group meetings on various aspects of population ageing.

This report is the fifth in the series *World Population Ageing*. The first report was released in 2002 in conjunction with the Second World Assembly on Ageing. The present report, which updates the 2007, 2009 and 2013 editions, provides a description of global trends in population ageing and includes new features on the socio-economic and health aspects of ageing. This report is accompanied by an interactive database on the *Profiles of Ageing 2015*.

This report was prepared by a team led by Jorge Bravo, including Sara Hertog, Yumiko Kamiya and Mun Sim Lai, who carried out research and drafted chapters. Ivan Prlincevic contributed programming and data processing and Donna Culpepper provided formatting and editorial support. Barney Cohen and John Wilmoth provided key guidance and useful comments on the draft report.

The present report has been issued without formal editing. Responsibility for the *World Population Ageing 2015* report rests with the Population Division.
# Explanatory notes

The following symbols have been used in the tables throughout this report:

Two dots (..) indicate that data are not available or are not separately reported.

An em dash (—) indicates that the amount is nil or negligible.

A hyphen (-) indicates that the item is not applicable.

A minus sign (-) before a figure indicates a decrease.

A point (.) is used to indicate decimals.

A slash (/) indicates a crop year or financial year, for example, 2010/15.

Use of a hyphen (-) between dates representing years, for example, 2010-2015, signifies the full period involved, including the beginning and end years.

Details and percentages in tables do not necessarily add to totals because of rounding.

Reference to “dollars” ($) indicates United States dollars, unless otherwise stated.

The term “billion” signifies a thousand million.
Sources, methods and classifications

Data on demographic trends used in the present report are taken from the 2015 Revision of the official United Nations world population estimates and projections (United Nations, Department of Economic and Social Affairs, Population Division, 2015). In addition, data on the levels of older persons' consumption and the sources of financing for that consumption are from the National Transfer Accounts database (2015). Data on labour force participation were obtained from the International Labour Organization (2015) and data on statutory retirement age from the United States Social Security Administration (2013 and 2014). Data on healthy life expectancy, causes of morbidity and mortality, and burden of disability were obtained from the World Health Organization (2014).

The population estimates and projections, which are prepared biennially by the Population Division of the Department of Economic and Social Affairs of the United Nations Secretariat, provide the standard and consistent set of population figures that are used throughout the United Nations system as the basis for activities requiring population information. In the 2015 Revision of the World Population Prospects, standard demographic techniques were used to estimate the population by age and sex, as well as trends in total fertility, life expectancy at birth, infant mortality and international migration for the years 1950 through 2015, from data available from censuses and post-enumeration surveys; demographic and health surveys; population and vital registration systems; scientific reports and data collections; and from data and estimates provided by international agencies. The resulting estimates provided the basis from which the population projections follow. In the 2015 Revision, the population projections are based on a probabilistic (Bayesian) method for projecting total fertility and life expectancy at birth. This method is based on empirical fertility and mortality trends estimated for all countries of the world for the period 1950 to 2015. The present report draws on the medium variant population projections through the year 2050.<fnref n="1" />

The countries and areas identified as statistical units by the Statistics Division of the United Nations and covered by the above estimates and projections, are grouped geographically into six regions: Africa; Asia; Europe; Latin America and the Caribbean; Northern America; and Oceania. The countries are also summarized, for statistical convenience, into two general groups—more developed and less developed—on the basis of demographic and socio-economic characteristics. The less developed regions include all regions of Africa, Asia (excluding Japan), Latin America and the Caribbean, and Oceania (excluding Australia and New Zealand). The more developed regions include all other regions plus the three countries excluded from the less developed regions. The group of least developed countries, as defined by the United Nations General Assembly in its resolutions (59/209, 59/210 and 60/33) in 2015 comprises 48 countries. In addition, the countries are summarized within four groups defined by the World Bank according to the gross national income (GNI) per capita in 2014: high-income countries are those with GNI per capita of $12,736 or more; upper-middle income countries are those with GNI per capita of more than $4,125 but less than $12,736; lower-middle income countries are those with GNI per capita of more than US$1,045 but less than $4,125; and low-income countries are those with GNI per capita of $1,045 or less. See Annex II for further detail on composition of the above mentioned groupings.

<footnote n="1">¹ Further information about data sources and methods underlying the estimates and projections of population can be found on the website of the Population Division at http://esa.un.org/unpd/wpp/.</footnote>
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# Contents

Page

<table><tr><td>Preface</td><td>iii</td></tr><tr><td>Explanatory notes</td><td>iv</td></tr><tr><td>Sources, methods and classifications</td><td>v</td></tr></table>

## Chapters

<table><tr><td>I.</td><td>INTRODUCTION AND KEY FINDINGS</td><td>1</td></tr><tr><td>II.</td><td>LEVELS AND TRENDS IN POPULATION AGEING</td><td>9</td></tr><tr><td></td><td>A. TRENDS IN THE NUMBERS OF OLDER PERSONS</td><td>9</td></tr><tr><td></td><td>B. DEMOGRAPHIC CHARACTERISTICS OF THE OLDER POPULATION</td><td>18</td></tr><tr><td></td><td>C. TRENDS IN THE PERCENTAGE OF OLDER PERSONS</td><td>23</td></tr><tr><td></td><td>D. DEPENDENCY AND SUPPORT RATIOS</td><td>34</td></tr><tr><td>III.</td><td>DEMOGRAPHIC DRIVERS OF POPULATION AGEING</td><td>41</td></tr><tr><td></td><td>A. FERTILITY AND MORTALITY AS DETERMINANTS OF TRENDS IN THE NUMBERS OF OLDER PERSONS</td><td>41</td></tr><tr><td></td><td>B. FERTILITY TRENDS</td><td>46</td></tr><tr><td></td><td>C. TRENDS IN LIFE EXPECTANCIES AND PROBABILITIES OF SURVIVAL TO OLD AGE</td><td>48</td></tr><tr><td></td><td>D. FERTILITY AND MORTALITY AS DETERMINANTS OF TRENDS IN THE PERCENTAGE OF OLDER PERSONS</td><td>57</td></tr><tr><td></td><td>E. INTERNATIONAL MIGRATION AND POPULATION AGEING</td><td>61</td></tr><tr><td>IV.</td><td>POPULATION AGEING AND SUSTAINABLE DEVELOPMENT</td><td>67</td></tr><tr><td></td><td>A. AGEING, POVERTY AND ECONOMIC GROWTH</td><td>67</td></tr><tr><td></td><td>B. POPULATION AGEING AND SOCIAL PROTECTION</td><td>77</td></tr><tr><td></td><td>C. POPULATION AGEING AND HEALTH</td><td>90</td></tr><tr><td></td><td>D. CONCLUSIONS</td><td>99</td></tr><tr><td></td><td>REFERENCES</td><td>103</td></tr></table>

## Annexes

<table><tr><td>I.</td><td>Glossary of terms related to population ageing</td><td>111</td></tr><tr><td>II.</td><td>Classification of regions and income groups</td><td>115</td></tr><tr><td>III.</td><td>Summary data tables</td><td>122</td></tr></table>
Figures

<table><tr><td>II.1.</td><td>Population aged 60-79 years and aged 80 years or over by development group, 2000, 2015, 2030 and 2050</td><td>11</td></tr><tr><td>II.2.</td><td>Population aged 60 years or over and aged 80 years or over by region, 1980-2050</td><td>13</td></tr><tr><td>II.3.</td><td>Population aged 60-79 years and aged 80 years or over by income group, 2000, 2015, 2030 and 2050</td><td>14</td></tr><tr><td>II.4.</td><td>Projected change in the population aged 60 years or over between 2015 and 2030 versus the level of gross national income per capita in 2014</td><td>15</td></tr><tr><td>II.5.</td><td>Population aged 60 years or over and aged 80 years or over by country, 2015</td><td>17</td></tr><tr><td>II.6.</td><td>Share of the global older population by age group and sex, 2015 and 2050</td><td>18</td></tr><tr><td>II.7.</td><td>Sex ratios of the population aged 60 years or over and aged 80 years or over for the world and regions, 2015 and 2050</td><td>19</td></tr><tr><td>II.8.</td><td>Percentage of oldest-old (aged 80 years or over) among the older population (aged 60 years or over) by region, 1980-2050</td><td>20</td></tr><tr><td>II.9.</td><td>Percentage change in the population aged 60 years or over between 2000 and 2015 for the world and regions, by urban/rural area</td><td>21</td></tr><tr><td>II.10.</td><td>Percentage urban by age group and region, 2015</td><td>22</td></tr><tr><td>II.11.</td><td>Percentage of population aged 60 years or over and aged 80 years or over residing in urban areas by region, 2000 and 2015</td><td>23</td></tr><tr><td>II.12.</td><td>Increase in world population relative to 2000 by broad age group, 2000-2050</td><td>24</td></tr><tr><td>II.13.</td><td>Global population by broad age group, 1950-2050</td><td>25</td></tr><tr><td>II.14.</td><td>Global population by broad age group, 2000, 2015, 2030 and 2050</td><td>25</td></tr><tr><td>II.15.</td><td>Percentage aged 60 years or over in 2015 versus gross national income per capita in 2014</td><td>28</td></tr><tr><td>II.16.</td><td>Percentage aged 60 years or over projected in 2030 versus gross national income per capita in 2014</td><td>28</td></tr><tr><td>II.17.</td><td>Percentage point change in the proportion aged 60 years or over for the world and regions, 2000-2015 and 2015-2030</td><td>30</td></tr><tr><td>II.18.</td><td>Percentage of the population aged 60 years or over for the world and regions, 1980-2050</td><td>31</td></tr><tr><td>II.19.</td><td>Maps of percentage of population aged 60 years or over in 2000, 2015 and 2050</td><td>33</td></tr><tr><td>II.20.</td><td>Total dependency ratio for the world and regions, 1950-2050</td><td>35</td></tr><tr><td>II.21.</td><td>Children and young people aged under 20 years and older persons aged 65 years or over as a percentage of the global population in the dependent ages, 1950-2100</td><td>36</td></tr><tr><td>II.22.</td><td>Average annual change in the economic support ratio, selected countries, 1980-2015 and 2015-2050</td><td>38</td></tr><tr><td>III.1.</td><td>Average annual percentage change in the population aged 60 years or over in 2010-2015 and total fertility in 1950-1955</td><td>42</td></tr><tr><td>III.2.</td><td>Average annual percentage change in the population aged 60 years or over in 2010-2015 and probability of survival to age 60 among the 1950-1955 birth cohort</td><td>43</td></tr><tr><td>III.3.</td><td>Average annual rate of change of the global population aged 60 years or over and aged 80 years or over, 1980-2050</td><td>45</td></tr><tr><td>III.4.</td><td>Total fertility rate for the world and regions, 1950-2050</td><td>46</td></tr><tr><td>III.5.</td><td>Average annual rate of change of the population aged 60 years or over, by region, 1980-2050</td><td>47</td></tr></table>
<table><tr><td>III.6.</td><td>Life expectancy at birth for the world and regions, 1950-2050</td><td>49</td></tr><tr><td>III.7.</td><td>Contribution of mortality decline at different ages to improvements in the life expectancy at birth between 1995-2000 and 2010-2015, for the world and regions</td><td>49</td></tr><tr><td>III.8.</td><td>Contribution of increased longevity after age 60 to total improvement in the life expectancy at birth, 1995-2000 to 2010-2015</td><td>51</td></tr><tr><td>III.9.</td><td>Life expectancy at age 60, by sex and region, 1950-2050</td><td>53</td></tr><tr><td>III.10.</td><td>Probabilities of survival to ages 60 and 80 years among the 1950-1955 and 2000-2005 birth cohorts, by sex and region</td><td>55</td></tr><tr><td>III.11.</td><td>Population age structure in Germany, Brazil and the United Republic of Tanzania, 1950, 2015 and 2050</td><td>59</td></tr><tr><td>III.12.</td><td>Percentage aged 60 years or over under three fertility projection scenarios, and total fertility rate (TFR), Japan, Pakistan and Nigeria, 1950-2050</td><td>60</td></tr><tr><td>III.13.</td><td>Distribution of countries according to the policy on immigration and level of concern about population ageing, 2005 and 2013</td><td>62</td></tr><tr><td>IV.1.</td><td>Poverty rate of older persons versus the poverty rate for the total population, recent estimates for selected countries</td><td>69</td></tr><tr><td>IV.2.</td><td>Levels of consumption per capita among older persons (aged 60 years or over) relative to the levels of consumption among those aged 30-49 years</td><td>73</td></tr><tr><td>IV.3.</td><td>Components of older persons' (aged 60 years or over) consumption, by income group</td><td>74</td></tr><tr><td>IV.4.</td><td>Ratio of older persons' (aged 60 years or over) consumption to that of persons aged 30-49 years and public transfers as a share of total consumption</td><td>75</td></tr><tr><td>IV.5.</td><td>Economic support ratio and demographic dividends in China, 1950-2050</td><td>76</td></tr><tr><td>IV.6.</td><td>Labour force participation of persons aged 65 years or over, by sex, 2015</td><td>79</td></tr><tr><td>IV.7.</td><td>Labour force participation of persons aged 65 years or over, by sex and region, 1990, 2000, 2015 and 2030</td><td>81</td></tr><tr><td>IV.8.</td><td>Distribution of countries according to the statutory retirement age, by sex and region, 2006 and 2015</td><td>83</td></tr><tr><td>IV.9.</td><td>Ratio of projected population aged 60 years or over in 2030 to estimated population aged 60 years or over in 2015 by level of pension coverage in 2010</td><td>85</td></tr><tr><td>IV.10.</td><td>Potential support ratio (persons aged 20-64 years per person aged 65 years or over), by region, 2015, 2030 and 2050</td><td>87</td></tr><tr><td>IV.11.</td><td>Pension expenditure (percentage of GDP) and potential support ratio by the size of the pension replacement rate for selected countries, 2015</td><td>88</td></tr><tr><td>IV.12.</td><td>Life expectancy at birth and healthy life expectancy at birth, by WHO region, 2013</td><td>92</td></tr><tr><td>IV.13.</td><td>Healthy years of life lost and life expectancy at birth, by country and sex, 2013</td><td>93</td></tr><tr><td>IV.14.</td><td>Changes in the population aged 60 years or over and NCD-related disability (YLDs) between 2000 and 2012</td><td>95</td></tr><tr><td>IV.15.</td><td>Years of life lost per capita due to disability and percentage of population aged 60 years of over in 2012</td><td>96</td></tr><tr><td>IV.16.</td><td>Change in percentage of older persons versus change in health care expenditures per capita, 2000-2013</td><td>99</td></tr></table>
Tables

Page

<table><tr><td>II.1</td><td>Population aged 60 years or over and aged 80 years or over for the world, development groups, regions and income groups, 2000, 2015, 2030 and 2050</td><td>10</td></tr><tr><td>II.2</td><td>Percentage aged 60 years or over and aged 80 years or over for the world, development groups, regions and income groups, 2000, 2015, 2030 and 2050</td><td>26</td></tr><tr><td>II.3</td><td>Ten countries or areas with the most aged populations, 2000, 2015 and 2030</td><td>29</td></tr><tr><td>II.4</td><td>Ten countries or areas with the largest percentage point changes in the proportion of the population aged 60 years or over, 2000-2015 and 2015-2030</td><td>32</td></tr><tr><td>III.1</td><td>Older population size and growth rate, and past fertility and mortality levels for the world and regions</td><td>44</td></tr><tr><td>III.2</td><td>Life expectancy at birth and at age 60, by sex, for the world and regions, 2010-2015</td><td>52</td></tr><tr><td>III.3</td><td>Life expectancy at age 60, by sex, for the world and regions, 1950-1955, 2010-2015 and 2045-2050</td><td>54</td></tr><tr><td>III.4</td><td>Ten leading causes of death of those aged 60 years or over globally, by sex, 2012</td><td>56</td></tr><tr><td>III.5</td><td>Countries or areas where international migration is projected to slow population ageing by at least 1 percentage point by 2030</td><td>64</td></tr><tr><td>III.6</td><td>Countries or areas where international migration is projected to accelerate population ageing by at least 1 percentage point by 2030</td><td>65</td></tr><tr><td>IV.1</td><td>Ten leading causes of disability globally among persons aged 60 years or over, by sex, 2012</td><td>97</td></tr></table>

Annex tables

<table><tr><td>A.III.1.</td><td>Population aged 60 years or over, percentage of population aged 60 years or over and median age, 2015, 2030 and 2050</td><td>122</td></tr><tr><td>A.III.2.</td><td>Fertility, life expectancy at birth and at age 60, and healthy life expectancy</td><td>127</td></tr><tr><td>A.III.3.</td><td>Dependency and support ratios, pension coverage, labour force participation and statutory retirement ages</td><td>132</td></tr><tr><td>A.III.4.</td><td>Ranking of countries or areas according to the estimated percentage of population aged 60 years or over, 2000 and 2015</td><td>138</td></tr><tr><td>A.III.5.</td><td>Ranking of countries or areas according to the projected percentage of population aged 60 years or over, 2030 and 2050</td><td>142</td></tr><tr><td>A.III.6.</td><td>Ranking of countries or areas according to the percentage point change in the proportion of the population aged 60 years or over, 2000-2015 and 2015-2030</td><td>146</td></tr></table>
# I. Introduction and key findings

The world's population is ageing: virtually every country in the world is experiencing growth in the number and proportion of older persons in their population. Population ageing—the increasing share of older persons in the population—is poised to become one of the most significant social transformations of the twenty-first century, with implications for nearly all sectors of society, including labour and financial markets, the demand for goods and services, such as housing, transportation and social protection, as well as family structures and inter-generational ties. Preparing for the economic and social shifts associated with an ageing population is thus essential to ensure progress in development, including towards the achievement of the goals outlined in the 2030 Agenda for Sustainable Development. Population ageing is particularly relevant for the goals on poverty eradication, ensuring healthy lives and well-being at all ages, promoting gender equality and full and productive employment and decent work for all, reducing inequalities between and within countries, and making cities and human settlements inclusive, safe, resilient and sustainable. The 2002 Madrid International Plan of Action on Ageing (MIPAA), adopted during the Second World Assembly on Ageing, highlighted the need to consider older persons in development planning, emphasizing that older persons should be able to participate in and benefit equitably from the fruits of development to advance their health and well-being, and that societies should provide enabling environments for them to do so. As populations become increasingly aged, it is more important than ever that governments design innovative policies and public services specifically targeted to older persons, including those addressing, *inter alia*, housing, employment, health care, infrastructure and social protection.

This report details the important changes that are taking place in the age structures of populations around the world. Chapter II describes recent and projected future levels and trends in the numbers and share of older persons in the population. It also presents trends in the demographic characteristics of the older population with respect to age, sex and urban/rural residence. Chapter III explores the demographic determinants—trends in fertility, mortality and migration—of changes to the size and age structure of the population. By adopting a historical perspective, this chapter identifies the major demographic shocks, as well as the more gradual demographic shifts, that shape current trends in population ageing. Chapter IV discusses the challenges posed by the growth in the number and share of older persons in the population for efforts to eradicate poverty and grow economies, to ensure the sustainability of pension systems, and to promote health and well-being at all ages. The issues highlighted in this chapter underscore just how critical the concerns of older persons are for progress in implementing the 2030 Agenda. The key findings of each of these chapters are summarized below:

## A. LEVELS AND TRENDS IN POPULATION AGEING

According to data from *World Population Prospects: the 2015 Revision* (United Nations, 2015), the number of older persons—those aged 60 years or over—has increased substantially in recent years in most countries and regions, and that growth is projected to accelerate in the coming decades.
* Between 2015 and 2030, the number of people in the world aged 60 years or over is projected to grow by 56 per cent, from 901 million to 1.4 billion, and by 2050, the global population of older persons is projected to more than double its size in 2015, reaching nearly 2.1 billion.

* Globally, the number of people aged 80 years or over, the "oldest-old" persons, is growing even faster than the number of older persons overall. Projections indicate that in 2050 the oldest-old will number 434 million, having more than tripled in number since 2015, when there were 125 million people over age 80.

* Over the next 15 years, the number of older persons is expected to grow fastest in Latin America and the Caribbean with a projected 71 per cent increase in the population aged 60 years or over, followed by Asia (66 per cent), Africa (64 per cent), Oceania (47 per cent), Northern America (41 per cent) and Europe (23 per cent).

* Globally, during 2010-2015, women outlived men by an average of 4.5 years. As a result, women accounted for 54 per cent of the global population aged 60 years or over and 61 per cent of those aged 80 years or over in 2015. In the coming years, average survival of males is projected to improve and begin to catch up to that of females so that the sex balance among the oldest-old persons becomes more even. The proportion of women at age 80 years or over is projected to decline to 58 per cent in 2050.

* Both improved longevity and the ageing of larger cohorts, including those born during the post-World War II baby boom, mean that the older population is itself ageing. The proportion of the world's older persons who are aged 80 years or over is projected to rise from 14 per cent in 2015 to more than 20 per cent in 2050.

* The older population is growing faster in urban areas than in rural areas. At the global level between 2000 and 2015, the number of people aged 60 years or over increased by 68 per cent in urban areas, compared to a 25 per cent increase in rural areas. As a result, older persons are increasingly concentrated in urban areas. In 2015, 58 per cent of the world's people aged 60 years or over resided in urban areas, up from 51 per cent in 2000. The oldest-old are even more likely to reside in urban areas: the proportion of people aged 80 years or over residing in urban areas increased from 56 per cent in 2000 to 63 per cent in 2015.

Globally, the number of older persons is growing faster than the numbers of people in any other age group. As a result, the share of older persons in the total population is increasing virtually everywhere. While population ageing is a global phenomenon, the ageing process is more advanced in some regions than in others, having begun more than a century ago in countries that developed earlier, and getting underway only recently in many countries where the development process has occurred later, including the decline of fertility.
* In 2015, one in eight people worldwide was aged 60 years or over. By 2030, older persons are projected to account for one in six people globally. By the middle of the twenty-first century, one in every five people will be aged 60 years or over.

* By 2030, older persons will outnumber children aged 0-9 years (1.4 billion versus 1.3 billion); by 2050, there will be more people aged 60 years or over than adolescents and youth aged 10-24 years (2.1 billion versus 2.0 billion).

* The ageing process is most advanced in high-income countries. Japan is home to the world's most aged population<fnref n="1" />: 33 per cent were aged 60 years or over in 2015. Japan is followed by Germany (28 per cent aged 60 years or over), Italy (28 per cent) and Finland (27 per cent).

* The pace of world population ageing is accelerating. Projections indicate that the proportion aged 60 years or over globally will increase more than 4 percentage points over the next 15 years, from 12.3 per cent in 2015 to 16.5 per cent in 2030, compared to the 2.3 percentage point increase in the share of older persons that occurred between 2000 and 2015.

* By 2030, older persons are expected to account for more than 25 per cent of the populations in Europe and in Northern America, 20 per cent in Oceania, 17 per cent in Asia and in Latin America and the Caribbean, and 6 per cent in Africa.

* In 2050, 44 per cent of the world's population will live in relatively aged countries, with at least 20 per cent of the population aged 60 years or over, and one in four people will live in a country where more than 30 per cent of people are above age 60.

* The pace of population ageing in many developing countries today is substantially faster than occurred in developed countries in the past. Consequently, today's developing countries must adapt much more quickly to ageing populations and often at much lower levels of national income compared to the experience of countries that developed much earlier.

## B. DEMOGRAPHIC DRIVERS OF POPULATION AGEING

Population ageing is in many ways a demographic success story, driven by changes in fertility and mortality that are associated with economic and social development. Progress in reducing child mortality, improving access to education and employment opportunities, advancing gender equality, and promoting reproductive health and access to family planning have all contributed to reductions in birth rates. Moreover, advancements in public health and medical technologies, along with improvements in living conditions, mean that people are living longer and, in many cases, healthier lives than ever before, particularly at advanced ages.

<footnote n="1">¹ Of the 201 countries or areas with at least 90,000 inhabitants in 2015.</footnote>
Together, these declines in fertility and increases in longevity are producing substantial shifts in the population age structure, such that the share of children is shrinking while that of older persons continues to grow.

* The growth rate of the population of older persons today is a function of the levels of fertility prevailing some 60 years ago when today's new cohorts of older persons were born, together with changes in the likelihood that members of those birth cohorts survived to older ages. Because fertility rates in the mid-twentieth century were higher in many parts of Africa, Asia and Latin America and the Caribbean—above five children per woman, on average—the growth rates of the older populations in those regions today are significantly faster than in Europe, where fertility in 1950-1955 had already fallen below three children per woman in many countries.

* Trends in the growth rate of the population of older persons reveal the powerful influence of major historical events in shaping the age composition of the population. The cohorts that entered their 80's during the late-1990's are those who were born during World War I, a time of depressed fertility in many countries that resulted in smaller birth cohorts. As a result, growth of the global population aged 80 years or over during 1995-2000 was slow relative to previous decades and has accelerated more recently as the cohorts born during the post-war fertility rebound reached their 80s.

* The fertility impact of World War II is evident in population ageing patterns as well. The growth rate of the global population aged 60 years or over has peaked in 2010-2015 and the rate of growth of the population aged 80 years or over is projected to peak in 2030-2035, marking the periods during which those born during the post-war baby boom reach older ages.

* Past and current regional levels of fertility predict the present and future rates of growth of their older populations. In Asia, the growth rate of the population of older persons is projected to decline precipitously after 2025, reflecting the rapid decline in fertility that began in the mid-1960s in that region. In Africa, the pace of growth of the population aged 60 years or over is projected to accelerate from just over 3 per cent per year in 2010-2015, reaching nearly 3.9 per cent per year in 2040-2045, reflecting the relatively high fertility rates of the region during the second half of the twentieth century. The pace of growth of the older population of Africa projected for the 2040s is faster than any region has experienced since 1950, when the data series begins.

* The immediate cause of population ageing is fertility decline. However, improved longevity contributes as well, first by eliminating the demographic necessity of high fertility and second by increasing the number of survivors to older ages. By 2050, life expectancy at birth is projected to surpass 80 years in Europe, Latin America and the Caribbean, Northern America and Oceania; and it will approach 80 years in Asia and 70 years in Africa.
* Improvements in survival at age 60 years or over have accounted for half of the total improvement in life expectancy in Europe, Northern America and Oceania over the past two decades. Reduced mortality at younger ages was more influential in improving the life expectancy at birth in Africa, Asia and Latin America and the Caribbean.

* In 2010-2015, 60-year-old persons globally could expect to live an additional 20.2 years, on average. Across the six regions, life expectancy at age 60 years was highest in Oceania and Northern America, at 23.7 years and 23.5 years, respectively, and lowest in Africa, at 16.7 years.

* Among today's young people, survival to age 80 is expected to be the norm everywhere but in Africa. Worldwide, 60 per cent of women and 52 per cent of men born in 2000-2005 are expected to survive to their eightieth birthdays, compared to less than 40 per cent of the women and men born in 1950-1955.

* While declining fertility and increasing longevity are the key drivers of population ageing globally, international migration has also contributed to changing population age structures in some countries and regions. However, in most countries, international migration is projected to have only small effects on the pace of population ageing. Between 2015 and 2030, net migration is projected to slow population ageing by at least 1 percentage point in 24 countries or areas, and to accelerate population ageing by at least 1 percentage point in 14 countries or areas.

## C. POPULATION AGEING AND SUSTAINABLE DEVELOPMENT

Growth in the numbers and proportions of older persons can be expected to have far reaching economic, social and political implications. In many countries the number of older persons is growing faster than the number of people in the traditional working ages, leading many governments to consider increasing the statutory ages at retirement in an effort to prolong the labour force participation of older persons and improve the financial sustainability of pension systems. At the same time, population ageing and growth in the number of persons at very advanced ages, in particular, puts pressure on health systems, increasing the demand for care, services and technologies to prevent and treat non-communicable diseases and chronic conditions associated with old age. Countries can address these and other challenges by anticipating the coming demographic shifts and enacting policies proactively to adapt to an ageing population.

### Ageing, poverty and economic growth

* In general, poverty rates among older persons tend to mirror fairly closely those of the population overall, although disparities are evident in some countries and regions. In many countries where pension systems are not in place or fail to
provide adequate income, including several in sub-Saharan Africa and in Asia, older persons are more likely to live in poverty than people at younger ages. Conversely, in countries with adequate pension systems with broad coverage, including several in Latin America and in Europe, poverty rates among older persons are essentially the same as or lower than those of the general population.

* Age patterns of consumption behaviour provide an additional indication of the level of welfare among older persons. In low-income and middle-income countries, levels of consumption tend to decline at older ages, indicating that older persons are faring less well than adults in other age groups in these countries. In contrast, in many high-income countries, the average levels of consumption among older persons are higher than among adults in other age groups—by as much as one third or more in some countries—indicating that older persons are comparatively well off in these countries.

* Public transfers, particularly for health care, play an important redistributive role to bolster the levels of consumption among older persons in many high-income countries. Conversely, in low-income and lower-middle-income countries, older persons finance most of their health care consumption through out-of-pocket expenditures. The low levels of public health expenditure in these countries contribute to a lack of health security and inferior care for older persons.

* Older persons' welfare is related to the share of consumption financed by public transfers. In many low-income countries where older persons are less well off than adults in other age groups, public transfers finance less than 15 per cent of total old-age consumption, compared to the 30 per cent or more of older persons' consumption that is financed by public transfers in many high-income countries, where older persons tend to be better off than adults in other age groups.

* Population ageing need not impede continued economic growth. Countries with increasing economic support ratios—thus, a rise in the ratio of producers to consumers in the population—benefit from a “first demographic dividend”. In societies where investments in human capital and savings accompany low fertility and increasing longevity motivates people to accumulate assets for old age, the increased volume of savings can further enhance economic growth, leading to a “second demographic dividend.” The second dividend is likely to be more significant in societies that do not rely solely on public or familial transfers to finance older persons’ consumption, but also promote retirement savings.

*Ensuring social protection for older persons and the sustainability of pension systems*

* Current demographic trends mean that each successive cohort of older persons can expect to live longer and possibly also have fewer adult children as potential sources of support in old age. In 2015, there were 7 people in the traditional working ages, 20-64 years, for each older person aged 65 years or over in the world. By 2050, there will be 3.5 working-aged people for each older person in
the world, and all major regions except Africa are expected to have potential support ratios of 3.2 or lower.

* Among people aged 65 years or over globally in 2015, 30 per cent of men and 15 per cent of women were active in the labour force. Older men and women in developing regions were more likely to be active in the labour force than their peers in the developed regions, due in part to differences in the structure and availability of pension systems across regions.

* In Europe, Oceania and Northern America, the labour force participation of older men has increased gradually since 1990, and it is projected to continue to increase in the future. In contrast, in Asia, Latin America and the Caribbean, and Africa, the labour force participation of older men has declined steadily. Among older women, labour force participation has increased since 1990 in all regions.

* In response to recent trends in population ageing, many low-income and middle-income countries have expanded the coverage of their contributory pension schemes and established non-contributory social pensions. Many high-income countries have undertaken fiscal consolidation reforms to their pension systems by raising the statutory pensionable age, reducing benefits or increasing contribution rates.

* At the global level, nearly half of all people who have reached statutory pensionable ages do not receive a pension, and for many of those who do receive a pension, the levels of support may be inadequate. Pension coverage is typically lower among women than among men owing to their lower rates of attachment to the labour market, their over-representation in the informal sector, or their work as self-employed or unpaid family workers. In many countries, the survivor's benefits paid through a husband's contributory pension benefits are the sole sources of income for older women.

## Promoting health and well-being at older ages

* Changes are needed around the globe to continue to adapt health systems to serve a growing number and proportion of older persons and to maximize health and well-being at all ages. The World Health Organization emphasizes that these changes need not imply exorbitant increases in national health budgets, even in countries with rapidly ageing populations. Indeed, technology-related changes in health care, growth in personal incomes and cultural norms and attitudes surrounding end-of-life care are far more influential than shifts in population age structure in driving increases in health care expenditures.

* Older persons are tremendously diverse with respect to their health and well-being. Understanding levels and trends in the prevalence and severity of disability is key to assessing the implications of ageing for population health. For the world as a whole in 2013, people lost an average of approximately nine years
of healthy life due to disability. In general, the number of healthy life years lost due to disability tends to be greater in countries with a higher life expectancy at birth. However, people living in countries with longer average lifespans tend to spend a smaller proportion of their lives with disability compared to countries where life expectancy is shorter. In Europe, the average nine years of healthy life lost due to disability in 2013 accounted for just under 12 per cent of the average 76-year lifespan, whereas in Africa the average eight years of healthy life lost due to disability accounted for nearly 14 per cent of the average 58-year lifespan.

* Whether the growing numbers of older persons are living their later years in good health is a crucial consideration for policy development. If the added years of life expectancy are spent with disability, then demographic trends could portend substantially increased demand for health care. If the onset or severity of ill health is instead postponed as life expectancy increases, then the pressures exerted on the health system by a growing population of older persons may be attenuated. So far, evidence of trends in the health status of older persons is mostly limited to high-income countries and points to different conclusions depending on the study or context, making it difficult to draw clear conclusions about the fundamental questions.

* Given the projected growth of the older population, which will occur in virtually every country of the world over the coming decades, health systems should prepare now to address the specific health concerns of older persons. Unipolar depressive disorders are the leading cause of disability among women aged 60 years or over, followed by hearing loss, back and neck pain, Alzheimer's disease and other dementias, and osteoarthritis. Among older men, hearing loss is the leading cause of disability, followed by back and neck pain, falls, chronic obstructive pulmonary disease and diabetes mellitus.

As populations continue to grow older during the post-2015 era, it is imperative that governments design innovative policies specifically targeted to the needs of older persons, including those addressing housing, employment, health care, social protection and other forms of intergenerational support. Because the coming demographic shifts are foreseeable with much clarity over the next few decades, governments are afforded the opportunity to adopt a proactive approach to align their policies to the evolving needs of an ageing population.
## II. Levels and trends in population ageing

### A. TRENDS IN THE NUMBERS OF OLDER PERSONS

The number of older persons in the world has increased substantially in recent years and that growth is projected to accelerate in the coming decades.

Worldwide, there were 901 million people aged 60 years or over in 2015, an increase of 48 per cent over the 607 million older persons globally in 2000 (table II.1; figure II.1). By 2030, the number of people in the world aged 60 years or over is projected to grow by 56 per cent, to 1.4 billion, and by 2050, the global population of older persons is projected to more than double its size in 2015, reaching nearly 2.1 billion.

Globally, the number of people aged 80 years or over, the “oldest-old” persons, is growing even faster than the number of older persons overall. In 2000, there were 71 million people aged 80 or over worldwide. Since then, the number of oldest-old grew by 77 per cent to 125 million in 2015, and it is projected to increase by 61 per cent over the next 15 years, reaching nearly 202 million in 2030. Projections indicate that in 2050 the oldest-old will number 434 million globally, having more than tripled in number since 2015.

Two thirds of the world's older persons live in the developing regions and their numbers are growing faster than in the developed regions.

The more developed regions were home to 38 per cent of the world's older persons in 2000, but that percentage fell to 33 per cent in 2015 and is projected to continue to fall, such that, in 2030, 27 per cent of the world's population aged 60 years or over will reside in the more developed regions. The growth rate of the older population of the more developed regions is projected to slow in the coming decades. While the number of people aged 60 years or over in developed regions grew by 29 per cent between 2000 and 2015, from 231 million to 299 million, it is projected to grow by 26 per cent over the next 15 years, reaching 375 million in 2030.

In contrast, in the developing regions, the growth of the population aged 60 years or over is accelerating. The number of older persons in the less developed regions grew from 376 million in 2000 to 602 million in 2015—an increase of 60 per cent—and it is projected to grow by 71 per cent between 2015 and 2030, when a projected 1 billion people aged 60 years or over will reside in the less developed regions. Projections indicate that 1.7 billion people aged 60 years or over—nearly 80 per cent of the world's older population—will live in the less developed regions in 2050.

In the recent past, the older population of the least developed countries was growing more slowly than in the other less developed countries. Between 2000 and 2015, the number of persons aged 60 years or over in the least developed countries increased by 54 per cent, compared to 61 per cent in the other less developed countries. However, growth in the number of older persons is accelerating more quickly in the least developed countries, such that, between 2015 and 2030, the projected 70 per cent increase in the population aged 60 years or over is
<table><caption>TABLE II.1. POPULATION AGED 60 YEARS OR OVER AND AGED 80 YEARS OR OVER FOR THE WORLD, DEVELOPMENT GROUPS, REGIONS AND INCOME GROUPS, 2000, 2015, 2030 AND 2050</caption><thead><tr><th rowspan="2"></th><th colspan="4">Persons aged 60 years or over<br>(millions)</th><th colspan="2">Percentage<br>change</th><th colspan="4">Distribution of older<br>persons (percentage)</th></tr><tr><th>2000</th><th>2015</th><th>2030</th><th>2050</th><th>2000-<br>2015</th><th>2015-<br>2030</th><th>2000</th><th>2015</th><th>2030</th><th>2050</th></tr></thead><tbody><tr><td>World</td><td>607.1</td><td>900.9</td><td>1402.4</td><td>2092.0</td><td>48.4</td><td>55.7</td><td>100.0</td><td>100.0</td><td>100.0</td><td>100.0</td></tr><tr><td><strong>Development groups</strong></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>More developed regions</td><td>231.3</td><td>298.8</td><td>375.2</td><td>421.4</td><td>29.2</td><td>25.6</td><td>38.1</td><td>33.2</td><td>26.8</td><td>20.1</td></tr><tr><td>Less developed regions</td><td>375.7</td><td>602.1</td><td>1027.2</td><td>1670.5</td><td>60.3</td><td>70.6</td><td>61.9</td><td>66.8</td><td>73.2</td><td>79.9</td></tr><tr><td>Other less developed countries</td><td>341.9</td><td>550.1</td><td>938.7</td><td>1484.9</td><td>60.9</td><td>70.6</td><td>56.3</td><td>61.1</td><td>66.9</td><td>71.0</td></tr><tr><td>Least developed countries</td><td>33.9</td><td>52.1</td><td>88.5</td><td>185.6</td><td>53.8</td><td>70.0</td><td>5.6</td><td>5.8</td><td>6.3</td><td>8.9</td></tr><tr><td><strong>Regions</strong></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Africa</td><td>42.4</td><td>64.4</td><td>105.4</td><td>220.3</td><td>51.9</td><td>63.5</td><td>7.0</td><td>7.2</td><td>7.5</td><td>10.5</td></tr><tr><td>Asia</td><td>319.5</td><td>508.0</td><td>844.5</td><td>1293.7</td><td>59.0</td><td>66.3</td><td>52.6</td><td>56.4</td><td>60.2</td><td>61.8</td></tr><tr><td>Europe</td><td>147.3</td><td>176.5</td><td>217.2</td><td>242.0</td><td>19.8</td><td>23.1</td><td>24.3</td><td>19.6</td><td>15.5</td><td>11.6</td></tr><tr><td>Latin America and the Caribbean</td><td>42.7</td><td>70.9</td><td>121.0</td><td>200.0</td><td>66.1</td><td>70.6</td><td>7.0</td><td>7.9</td><td>8.6</td><td>9.6</td></tr><tr><td>Oceania</td><td>4.1</td><td>6.5</td><td>9.6</td><td>13.2</td><td>56.2</td><td>47.4</td><td>0.7</td><td>0.7</td><td>0.7</td><td>0.6</td></tr><tr><td>Northern America</td><td>51.0</td><td>74.6</td><td>104.8</td><td>122.7</td><td>46.4</td><td>40.5</td><td>8.4</td><td>8.3</td><td>7.5</td><td>5.9</td></tr><tr><td><strong>Income groups</strong></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>High-income countries</td><td>230.8</td><td>309.7</td><td>408.9</td><td>483.1</td><td>34.2</td><td>32.0</td><td>38.0</td><td>34.4</td><td>29.2</td><td>23.1</td></tr><tr><td>Upper-middle-income countries</td><td>195.2</td><td>320.2</td><td>544.9</td><td>800.6</td><td>64.0</td><td>70.2</td><td>32.1</td><td>35.5</td><td>38.9</td><td>38.3</td></tr><tr><td>Lower-middle-income countries</td><td>159.7</td><td>237.5</td><td>393.9</td><td>692.5</td><td>48.8</td><td>65.9</td><td>26.3</td><td>26.4</td><td>28.1</td><td>33.1</td></tr><tr><td>Low-income countries</td><td>21.2</td><td>33.2</td><td>54.0</td><td>114.8</td><td>56.2</td><td>63.0</td><td>3.5</td><td>3.7</td><td>3.9</td><td>5.5</td></tr></tbody></table>

<table><thead><tr><th rowspan="2"></th><th colspan="4">Persons aged 80 years or over<br>(millions)</th><th colspan="2">Percentage<br>change</th><th colspan="4">Distribution of oldest-old<br>persons (percentage)</th></tr><tr><th>2000</th><th>2015</th><th>2030</th><th>2050</th><th>2000-<br>2015</th><th>2015-<br>2030</th><th>2000</th><th>2015</th><th>2030</th><th>2050</th></tr></thead><tbody><tr><td>World</td><td>71.0</td><td>125.3</td><td>201.8</td><td>434.4</td><td>76.5</td><td>61.1</td><td>100.0</td><td>100.0</td><td>100.0</td><td>100.0</td></tr><tr><td><strong>Development groups</strong></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>More developed regions</td><td>36.5</td><td>59.1</td><td>85.2</td><td>127.8</td><td>61.8</td><td>44.1</td><td>51.5</td><td>47.2</td><td>42.2</td><td>29.4</td></tr><tr><td>Less developed regions</td><td>34.4</td><td>66.2</td><td>116.6</td><td>306.7</td><td>92.1</td><td>76.3</td><td>48.5</td><td>52.8</td><td>57.8</td><td>70.6</td></tr><tr><td>Other less developed countries</td><td>32.0</td><td>61.4</td><td>108.2</td><td>285.9</td><td>91.6</td><td>76.3</td><td>45.1</td><td>49.0</td><td>53.6</td><td>65.8</td></tr><tr><td>Least developed countries</td><td>2.4</td><td>4.8</td><td>8.4</td><td>20.7</td><td>99.2</td><td>75.4</td><td>3.4</td><td>3.8</td><td>4.2</td><td>4.8</td></tr><tr><td><strong>Regions</strong></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Africa</td><td>3.0</td><td>5.7</td><td>9.3</td><td>22.2</td><td>85.7</td><td>64.3</td><td>4.3</td><td>4.5</td><td>4.6</td><td>5.1</td></tr><tr><td>Asia</td><td>30.9</td><td>60.0</td><td>103.7</td><td>255.7</td><td>94.0</td><td>73.0</td><td>43.6</td><td>47.9</td><td>51.4</td><td>58.8</td></tr><tr><td>Europe</td><td>21.2</td><td>34.6</td><td>46.1</td><td>71.0</td><td>63.0</td><td>33.2</td><td>29.9</td><td>27.6</td><td>22.8</td><td>16.4</td></tr><tr><td>Latin America and the Caribbean</td><td>5.1</td><td>10.3</td><td>18.7</td><td>44.8</td><td>101.4</td><td>81.4</td><td>7.2</td><td>8.2</td><td>9.3</td><td>10.3</td></tr><tr><td>Oceania</td><td>0.7</td><td>1.1</td><td>2.0</td><td>3.6</td><td>69.8</td><td>76.8</td><td>1.0</td><td>0.9</td><td>1.0</td><td>0.8</td></tr><tr><td>Northern America</td><td>10.0</td><td>13.6</td><td>22.0</td><td>37.2</td><td>36.1</td><td>61.7</td><td>14.1</td><td>10.9</td><td>10.9</td><td>8.6</td></tr><tr><td><strong>Income groups</strong></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>High-income countries</td><td>37.0</td><td>60.9</td><td>90.9</td><td>145.4</td><td>64.5</td><td>49.3</td><td>52.2</td><td>48.6</td><td>45.0</td><td>33.5</td></tr><tr><td>Upper-middle-income countries</td><td>19.0</td><td>37.2</td><td>66.6</td><td>182.5</td><td>96.2</td><td>79.0</td><td>26.7</td><td>29.7</td><td>33.0</td><td>42.0</td></tr><tr><td>Lower-middle-income countries</td><td>13.5</td><td>24.4</td><td>39.3</td><td>94.8</td><td>80.9</td><td>61.1</td><td>19.0</td><td>19.5</td><td>19.5</td><td>21.8</td></tr><tr><td>Low-income countries</td><td>1.5</td><td>2.7</td><td>4.9</td><td>11.3</td><td>83.6</td><td>80.9</td><td>2.1</td><td>2.2</td><td>2.4</td><td>2.6</td></tr></tbody></table>

Data source: United Nations (2015). *World Population Prospects: The 2015 Revision*.
nearly identical to that projected in the other less developed countries (71 per cent). Despite such rapid growth however, the least developed countries collectively are projected to account for just 6.3 per cent of the global population aged 60 years or over in 2030 and 8.9 per cent in 2050, up from 5.8 per cent in 2015.

<figure><img src="image_6.png" /><figcaption>Figure II.1.
Population aged 60-79 years and aged 80 years or over by development group, 2000, 2015, 2030 and 2050</figcaption></figure>

Data source: United Nations (2015). *World Population Prospects: The 2015 Revision*.

In 2050, two out of every three oldest-old persons will live in developing regions.

The cohorts born during World War II will enter their 80s during 2015-2030. Because fertility was depressed during the war, resulting in smaller birth cohorts, the population aged 80 years or over is projected to grow more slowly over the coming 15 years than over the previous 15 years.<fnref n="2" /> In the more developed regions, the number of oldest-old persons grew by 62 per cent over the previous 15-year period, from 37 million in 2000 to 59 million in 2015, but it is projected to grow by 44 per cent over the next 15 years, reaching 85 million in 2030. The number of oldest-old persons residing in the less developed regions in 2000, 34 million, was very similar to the number in the more developed regions. However, the population aged 80 years or over is growing faster in the less developed regions than in the more developed regions: it increased by more than 92 per cent between 2000 and 2015 and is projected to grow further by 76 per cent between 2015 and 2030. Consequently, the world's oldest-old persons are increasingly concentrated in the developing regions, from 49 per cent in 2000 to 53 per cent in 2015, and that proportion is projected to rise further to 58 per cent in 2030 and to 71 per cent in 2050.

The number of oldest-old persons in the least developed countries nearly doubled between 2000 and 2015, from 2.4 million to 4.8 million persons aged 80 years or over, and their number

<footnote n="2">² See chapter III for a discussion of the historical drivers of trends in the size of the older population.</footnote>
is projected to continue to grow, albeit at a somewhat slower pace than in the past, reaching 8.4 million in 2030. In 2015, the least developed countries were home to 3.8 per cent of the global population aged 80 years or over, and by 2050 their share of the world's oldest-old persons is projected to rise to 4.8 per cent.

**Over the next 15 years, the number of older persons is expected to grow fastest in Latin America and the Caribbean with a projected 71 per cent increase in the population aged 60 years or over, followed by Asia (66 per cent) and Africa (64 per cent).**

With 508 million people aged 60 years or over in 2015, Asia was home to 56 per cent of the global older population, and, in 2030, Asia's share of the world's older persons is projected to increase to 60 per cent when a projected 845 million people aged 60 years or over will reside in the region (table II.1; figure II.2). According to projections, by 2030, Asia will be home to more than half of the world's oldest-old persons as well, up from 48 per cent in 2015. Moreover, projections indicate that in 2050, nearly 62 per cent of people aged 60 years or over and 59 per cent of people aged 80 years or over will reside in Asia.

Latin America and the Caribbean's 71 million older persons in 2015 accounted for 7.9 per cent of the global total. The share of the world's older persons residing in this region is expected to grow to 8.6 per cent in 2030, when a projected 121 million people aged 60 years or over will live there. Africa was home to a relatively small number of people aged 60 years or over, with 64 million in 2015, representing 7.2 per cent of the global total. In 2030, Africa's projected 105 million older persons could account for 7.5 per cent of the older population worldwide.

Latin America and the Caribbean is expected to see the fastest growth in the number of oldest-old persons as well, with an increase of 81 per cent between 2015 and 2030, which is a legacy of high fertility rates some 80 years prior, as well as increased longevity. The region is followed by Oceania, with a 77 per cent projected increase in the number of oldest-old over the same period, Asia (73 per cent) and Africa (64 per cent).

**Europe and Northern America are projected to see substantial increases in the numbers of older persons, but growth will be slower there than in the other regions.**

The share of the world's older persons residing in Europe and Northern America is expected to decline. In 2000, Europe's 147 million people aged 60 years or over accounted for close to one in four older persons globally and while their numbers grew to 177 million in 2015, their share of the world's older population fell to just under 20 per cent. Europe's older persons are projected to grow in number to 217 million in 2030, representing a 23 per cent increase over 2015, but given that this growth is slower than in the other regions, the share of the world's older persons residing in Europe in 2030 is projected to fall below 16 per cent. By 2050, the projected 242 million older persons in Europe would account for just 12 per cent of the global population aged 60 years or over.

In a trend similar to Europe's, the number of people aged 60 years or over in Northern America has grown from 51 million in 2000 to 75 million in 2015 and is projected to rise further to 105 million in 2030 and 123 million in 2050, while the share of the world's older persons
residing in Northern America is projected to decline from 8.3 per cent in 2015 to 7.5 per cent in 2030 and to 5.9 per cent in 2050.

<figure><img src="image_7.png" /><figcaption>**Figure II.2.** Population aged 60 years or over and aged 80 years or over, by region, 1980-2050</figcaption></figure>

Data source: United Nations (2015). *World Population Prospects: The 2015 Revision.*

From 2000 to 2015, the number of oldest-old persons in Europe grew much faster than the overall number of older persons (63 per cent versus 20 per cent), but the rate of increase of the population aged 80 years or over is projected to slow in the coming years, growing by 33 per cent between 2015 and 2030, compared to 23 per cent for the overall population aged 60 years or over. Again, these trends are highly influenced by excess mortality and reduced fertility during World War II, when the coming cohorts of oldest-old persons were born. In contrast, the growth in the number of people aged 80 years or over in Northern America is projected to accelerate: the population of oldest-old persons grew by 36 per cent between 2000 and 2015, from 10 million to 13.6 million and it is projected to rise by 62 per cent between 2015 and 2030, when a projected 22 million people aged 80 years or over will reside in Northern America.

**Growth in the number of older persons was fastest in upper-middle-income countries between 2000 and 2015, and this group of countries is expected to see the fastest growth in the older population between 2015 and 2030 as well.**

The 320 million people aged 60 years or over in upper-middle-income countries in 2015 represented a 64 per cent increase over 2000 when older persons in those countries numbered
195 million (table II.1; figure II.3). Between 2015 and 2030, upper-middle-income countries are anticipated to continue to experience rapid growth in the number of older persons: the projected 545 million people aged 60 years or over in 2030 marks a 70 per cent increase over the number in 2015.

<figure><img src="image_8.png" /><figcaption>Figure II.3. Population aged 60-79 years and aged 80 years or over by income group, 2000, 2015, 2030 and 2050</figcaption></figure>

Data source: United Nations (2015). *World Population Prospects: The 2015 Revision.*

The older populations of lower-middle-income countries and low-income countries grew at a slower average pace between 2000 and 2015, increasing by 49 per cent and 56 per cent, respectively. The growth rates are projected to accelerate in both groups of countries in the coming years. Between 2015 and 2030, the older population in lower-middle-income countries is projected to increase by 66 per cent, from 238 million to 394 million, while that in low-income countries is projected to grow by 63 per cent, from 33 million to 54 million.

Owing to longer average survival in the high-income countries relative to the other income groups, a plurality of the world's oldest-old persons are concentrated in this group of countries. In 2015, close to 49 per cent of the global population aged 80 years or over lived in high-income countries, and, while the proportion is projected to decline somewhat, by 2030 high-income countries are expected to continue to account for 45 per cent of the oldest-old persons in the world. Of the four income groups, the number of oldest-old persons is projected to grow most rapidly in low-income countries, where the coming cohorts of oldest-old persons were born within contexts of very high fertility around the middle of the twentieth century. The low-income countries as a group are expected to see an 81 per cent increase in the number of oldest-old persons between 2015 and 2030, followed by upper-middle-income countries, with a 79 per cent increase in the population aged 80 years or over projected for the same period.

Virtually every country in the world will experience a substantial increase in the size of the population aged 60 years or over between 2015 and 2030.
Within each of the development groups, regions and income groups there is a great deal of heterogeneity in the growth rates of the older population. Figure II.4 shows the projected percentage change in the number of older persons between 2015 and 2030 plotted according to the level of gross national income (GNI) per capita in 2014 for the 190 countries with at least 90,000 inhabitants in 2015 and for which GNI information was available, with regions distinguished by colour. The chart illustrates that while growth in the population aged 60 years or over is expected across all major income groups and regions of the world, the projected growth rates vary considerably from country to country.

<figure><img src="image_9.png" /><figcaption>**Figure II.4.** Projected change in the population aged 60 years or over between 2015 and 2030 versus the level of gross national income per capita in 2014</figcaption></figure>

*Data sources:* United Nations (2015). *World Population Prospects: The 2015 Revision* and World Bank (2015). World Development Indicators (http://data.worldbank.org/indicator/NY.GNP.PCAP.CD), accessed 26 August 2015.

Among the 29 low-income countries depicted in figure II.4, most of which are located in sub-Saharan Africa, the projected growth in the population aged 60 years or over between 2015 and 2030 ranges from 41 per cent in the Central African Republic to 88 per cent in Rwanda. In just over half of the low-income countries, growth in the number of older persons is projected to exceed 60 per cent between 2015 and 2030.
Middle-income countries are anticipating similarly rapid growth in the numbers of older
persons between 2015 and 2030. Of the 100 middle-income countries depicted in figure II.4, 67
per cent are projected to see greater than 60 per cent growth in the number of older persons
during that period and one in four middle-income countries are projected to experience increases
of more than 80 per cent. In India, for example, the number of older persons is projected to grow
by 64 per cent between 2015 and 2030, while in China it is projected to grow by 71 per cent over
the same period. In Tajikistan, Mongolia, the Maldives and Libya, the number of older persons is
projected to more than double by 2030. In each of these four countries, total fertility exceeded
six children per woman during the 1960s and 1970s, when the coming cohorts of older persons
were born.<fnref n="3" /> Projected growth of the population aged 60 years or over also exceeds 90 per cent in
nine other middle-income countries or areas: Azerbaijan, Bangladesh, Belize, Guyana, Iran,
Kiribati, Kyrgyzstan, the State of Palestine and Viet Nam.

Projected growth rates tend to be slower, on average, for the older populations of high-
income countries. Among the 61 high-income countries depicted in figure II.4, less than one
third are projected to see greater than 60 per cent growth in the number of older persons between
2015 and 2030, while the projected growth is between 20 and 60 per cent in another one third of
countries. Within the high-income group, projected growth in the older population tends to be
higher in countries of Asia. Examples include Singapore, which is expected to see a 97 per cent
increase in the population aged 60 years or over between 2015 and 2030, and the Republic of
Korea with a projected 77 per cent increase over the same period. Projected growth tends to be
lower, on average, in high-income countries of Europe and in Latin America and the Caribbean.
Examples include Finland, with a 20 per cent projected increase in the population aged 60 years
or over between 2015 and 2030, and Uruguay, with a 21 per cent projected increase.

Of the 201 countries or areas with 90,000 inhabitants or more in 2015, only 9 are expected to see a less than 10 per cent increase in the population aged 60 years or over between 2015 and 2030. This includes several Eastern European and Baltic States—Bulgaria, Estonia, Hungary, Latvia, Lithuania, Serbia and Ukraine—where multiple demographic factors result in little or no growth in the number of older persons, such as low levels of fertility at the time the coming cohorts of older persons were born, relatively high mortality among adults, and high rates of emigration in some countries. Outside of Eastern Europe, Japan is projected to see growth in the number of older persons of only 7 per cent between 2015 and 2030, owing to very low fertility rates over a number of decades. Lesotho, a country highly affected by excess mortality caused by HIV and AIDS, is projected to experience a small decline in the number of older persons of just over 1 per cent between 2015 and 2030.

In 2015, just twenty countries accounted for three quarters of the world's older population.

Nearly one in four persons aged 60 years or over in the world in 2015 lived in China (figure
II.5, left chart). Taken together, just five countries—China, India, the United States, Japan and
the Russian Federation—accounted for half of the world's population aged 60 years or over in
2015. The world's population aged 80 years or over was similarly concentrated in a small
number of countries. The five countries with the largest number of oldest-old persons—China,
the United States, India, Japan and Germany—collectively accounted for 48 per cent of the

<footnote n="3">³ See chapter III for a discussion of the demographic drivers of the pace of growth of the older population.</footnote>
world's oldest-old in 2015 and 19 countries held three quarters of the global population aged 80 years or over (figure II.5, right chart).

<figure><img src="image_10.png" /><figcaption>**Figure II.5.**
Population aged 60 years or over and aged 80 years or over by country, 2015</figcaption></figure>

Data source: United Nations (2015). World Population Prospects: The 2015 Revision.
## B. DEMOGRAPHIC CHARACTERISTICS OF THE OLDER POPULATION

Women tend to live longer than men, on average, and thus comprise a majority of older persons, especially at advanced ages.

Globally, women outlived men by an average of 4.5 years during the period 2010-2015.<fnref n="4" /> In 2015, women accounted for 54 per cent of the global population aged 60 years or over and 61 per cent of those aged 80 years or over (figure II.6).

<figure><img src="image_11.png" /><figcaption>Figure II.6. Share of the global older population by age group and sex, 2015 and 2050</figcaption></figure>

Data source: United Nations (2015). *World Population Prospects: The 2015 Revision.*

The sex balance of the older population is projected to remain relatively unchanged at the global level in the coming decades.

Projections indicate that in 2050, women will comprise 53 per cent of the world's population aged 60 years or over. Since average survival of males is projected to gradually move closer to that of females, the sex balance among the oldest-old will become more even. The proportion of women aged 80 years or over is projected to decline to 58 per cent in 2050.

The sex ratio—traditionally expressed as the number of men per 100 women—is a useful measure for describing the sex balance of the older population and trends therein. At the global level, there were 86 men for every 100 women aged 60 years or over in 2015 and 63 men for every 100 women aged 80 years or over. Those ratios are projected to rise to 89 and 73, respectively, in 2050 (figure II.7).

<footnote n="4">⁴ See chapter III for a discussion of trends in the life expectancies at birth and at older ages.</footnote>
<figure><img src="image_12.png" /><figcaption>**Figure II.7.**
Sex ratios of the population aged 60 years or over and aged 80 years or over for the world and regions, 2015 and 2050</figcaption></figure>

Data source: United Nations (2015). *World Population Prospects: The 2015 Revision.*

The sex ratio of the older population is lowest in Europe and highest in Asia.

In 2015, across the world's regions, the sex balance of the older population was most uneven (as indicated by low sex ratios) in Europe, where there were just 73 men per 100 women aged 60 years or over and 51 men per 100 women aged 80 years or over. The sex balance was most even in Asia, where there were 91 men per 100 women aged 60 years or over and 70 men per 100 women aged 80 years or over.

Between 2015 and 2050, the sex balance of the population aged 60 years or over is projected to become more even in Europe, Northern America, Latin America and the Caribbean and Africa, as the female advantage in life expectancy at age 60 is expected to narrow somewhat in these regions. At ages 80 or over, the sex balance of the population is projected to become more even between 2015 and 2050 in all regions except Africa. In general, increasing sex ratios among oldest-old persons reflect that improvements in the life expectancy at age 80 are occurring at a faster pace among males than among females.
The older population is itself ageing.

As a result of both improved longevity and the ageing of large cohorts (that is, the “baby boomers” born during the post-World War II period), the world’s older population is projected to become increasingly aged. Globally, the share of the older population that is aged 80 years or over rose from 9 per cent in 1980 to 14 per cent in 2015 (figure II.8), and it is projected to remain fairly stable between 2015 and 2030. Between 2030 and 2050 the proportion of the world’s older persons that are aged 80 years or over is projected to rise from 14 per cent to more than 20 per cent.

<figure><img src="image_13.png" /><figcaption>Figure II.8.
Percentage of oldest-oldest old (aged 80 years or over) among the older population (aged 60 years or over) by region, 1980-2050</figcaption></figure>

Data source: United Nations (2015). *World Population Prospects: The 2015 Revision*.

By 2040, the oldest-old are projected to account for one in four older persons in Europe, Northern America and Oceania.

In 2015, Europe had the most aged population of older persons, with people aged 80 years or over accounting for nearly one in five of those aged 60 years or over in the region. The older populations of Latin America and the Caribbean, Asia and Africa were much younger by comparison in 2015: people aged 80 years or over accounted for just 15 per cent, 12 per cent and 9 per cent, respectively, of the older populations in those three regions. According to projections, the proportion of the older population aged 80 years or over will surpass 25 per cent by 2040 in Europe, Northern America and Oceania. By 2050, the oldest-old are projected to account for 30 per cent of older persons in Northern America, 29 per cent of older persons in Europe and 27 per cent of older persons in Oceania. The older populations of Latin America and the Caribbean and Asia are projected to age considerably between 2030 and 2050, as well. In 2050, the oldest-old are projected to account for 22 per cent of older persons in Latin America and the Caribbean and 20 per cent of older persons in Asia. The older population of Africa is projected to age more slowly such that in 2050, people aged 80 years or over will account for 10 per cent of the overall population of older persons in the region.
The older population is growing faster in urban areas than in rural areas.<fnref n="5" />

At the global level, between 2000 and 2015, the number of people aged 60 years or over increased by 68 per cent in urban areas, compared to a 25 per cent increase in rural areas (figure II.9). Growth in the number of older persons in urban areas outpaced that in rural areas in all regions except Oceania, where the rapidly growing cohorts of older persons in the comparatively rural populations of Melanesia, Micronesia and Polynesia exceed the pace of growth of the urban older populations in the more urbanized countries of Australia and New Zealand. In Asia, the number of people aged 60 years or over in urban areas in 2015 was more than double the number in 2000 (a 106 per cent increase), while in Asia's rural areas the number of older persons increased by just 28 per cent over the same period. In Europe, the older population in rural areas barely changed in size between 2000 and 2015, growing by just 2 per cent, at the same time the older population in urban areas increased by 26 per cent. In general, the regions that are urbanizing the fastest—Latin America and the Caribbean, Asia and Africa—saw the biggest differentials in the growth of the number of older persons between urban and rural areas.

<figure><img src="image_14.png" /><figcaption>**Figure II.9.** Percentage change in the population aged 60 years or over between 2000 and 2015 for the world and regions, by urban/rural area</figcaption></figure>

Data source: United Nations (2014a). *Urban and rural population by age and sex (URPAS), 1980-2015* (version 3, August 2014).

The faster growth of the older population in urban areas compared to rural areas is likely attributable both to trends in the urbanization of the population across all age groups and to differences in mortality risks, which tend to be lower in urban areas relative to rural areas (see

<footnote n="5">⁵ The data presented in this section are from United Nations (2014). *Urban and rural population by age and sex (URPAS), 1980-2015* (version 3, August 2014), which reflects estimates of population disaggregated by age, sex and urban and rural residence consistent with the 2012 *Revision of World Population Prospects*.</footnote>
for instance: Singh and Siahpush, 2014; Zimmer, Kaneda and Spess, 2007; Van De Poel, O'Donnell and Van Doorslaer, 2007).

**Globally, the proportion of older persons residing in urban areas is higher than for other age groups.**

In 2015, 58 per cent of older persons globally lived in urban areas, compared to 46 per cent of children aged 0 to 14 years, 54 per cent of adolescents and youth aged 15 to 24 years and 57 per cent of people aged 25 to 59 years (figure II.10). The age patterns of urban residence vary somewhat across regions. In Africa, both children and older persons were less likely to live in urban areas than people in the working ages (37 per cent versus 44 per cent). In Asia, Europe and Latin America and the Caribbean, the share residing in urban areas was similar across the 15-24, 25-59 and 60 or over age groups. In Northern America, older persons were somewhat less likely to reside in urban areas (78 per cent) compared to children (82 per cent), adolescents and youth (85 per cent), and people aged 25-59 years (82 per cent). In Oceania, older persons were substantially more likely to live in urban areas relative to children aged 0-14 years (81 per cent versus 60 per cent), reflecting the region's concentration of older persons in the highly urbanized countries of Australia and New Zealand and the comparatively young age structures of the more rural populations of Melanesia, Micronesia and Polynesia.

<figure><img src="image_15.png" /><figcaption>**Figure II.10.**
Percentage urban by age group and region, 2015</figcaption></figure>

*Data source: United Nations (2014a). *Urban and rural population by age and sex (URPAS)*, 1980-2015 (version 3, August 2014).*

**The older population is increasingly concentrated in urban areas.**
In 2015, 58 per cent of the world's people aged 60 years or over resided in urban areas, up from 51 per cent in 2000 (figure II.11). The oldest-old are even more likely to reside in urban areas: the proportion of people aged 80 years or over residing in urban areas rose from 56 per cent in 2000 to 63 per cent in 2015. In Oceania, more than 80 per cent of older persons resided in urban areas and 90 per cent of the oldest-old resided in urban areas in 2015. In Northern America and Latin America and the Caribbean, 76 per cent of older persons lived in urban areas in 2000 and the proportions rose to 78 per cent and 81 per cent in 2015 for the two regions, respectively. More than 8 in 10 oldest-old persons in Northern America and Latin America and the Caribbean resided in urban areas in 2015.

<figure><img src="image_16.png" /><figcaption>**Figure II.11.** Percentage of population aged 60 years or over and aged 80 years or over residing in urban areas by region, 2000 and 2015</figcaption></figure>

Data source: United Nations (2014a). Urban and rural population by age and sex (URPAS), 1980-2015 (version 3, August 2014).

The share of older persons residing in urban areas in Europe rose from 68 per cent in 2000 to 72 per cent in 2015. Asia saw the largest increase in the proportion urban among its older population: the percentage of those aged 60 years or over residing in urban areas increased from 37 per cent in 2000 to 49 per cent in 2015. The oldest-old population in Asia urbanized even faster: 53 per cent of those aged 80 years or over lived in urban areas in 2015, up from 38 per cent in 2000. In Africa, the world's least urbanized region, close to 37 per cent of older persons lived in urban areas in 2015, up from 31 per cent in 2000.

### C. TRENDS IN THE PERCENTAGE OF OLDER PERSONS

While growth in the number of older persons is an important trend in itself, the process of population ageing, by definition, refers to an increasing proportion of older persons in a population. Thus, ageing is determined not only by the pace of growth of the older population, but also by how that pace compares to the growth rates of the other age groups.
Globally, the number of older persons is growing faster than the numbers of people in any other age group.

In 2015, there were 48 per cent more people aged 60 years or over worldwide than there were in 2000, and by 2050, the number of older people is projected to have more than tripled since 2000 (figure II.12). In contrast, at the global level, the numbers of children under age 10 and adolescents and youth aged 10-24 years will change very little: the projected numbers of children and adolescents and youth in 2050 represents an 11 per cent increase over the year 2000. The global number of adults aged 25-59 years is growing faster than the number of children, but not as fast as the population aged 60 years or over. In 2015, there were 29 per cent more people aged 25-59 years than there were in 2000, and projections indicate that by 2050 there will be 62 per cent more of them than in 2000.

<figure><img src="image_17.png" /><figcaption>**Figure II.12.** Increase in world population relative to 2000, by broad age group, 2000-2050</figcaption></figure>

*Data source: United Nations (2015). World Population Prospects: The 2015 Revision.*

Historically, the population of older persons has been much smaller than any other of these age groups. In 1960, for example, children under age 10 outnumbered people aged 60 years or over by more than 3 to 1, and there were nearly five times as many people aged 25-59 years as older persons (figure II.13). By 2000, however, the ratio of children to older persons had fallen to 2 to 1 (1.2 billion versus 0.6 billion), while that of people aged 25-59 to older persons had fallen close to 4 to 1 (2.6 billion versus 0.6 billion) (figure II.14). By 2030, older persons are projected to outnumber children aged 0-9 years (1.4 billion versus 1.3 billion); by 2050, there will be more people aged 60 years or over than adolescents and youth aged 10-24 years (2.1 billion versus 2.0 billion).
<figure><img src="image_18.png" /><figcaption>**Figure II.13.**
Global population by broad age group, 1950-2050</figcaption></figure>

*Data source: United Nations (2015). World Population Prospects: The 2015 Revision.*

<figure><img src="image_19.png" /><figcaption>**Figure II.14.**
Global population by broad age group, 2000, 2015, 2030 and 2050</figcaption></figure>

*Data source: United Nations (2015). World Population Prospects: The 2015 Revision.*
<table><caption>TABLE II.2. PERCENTAGE AGED 60 YEARS OR OVER AND AGED 80 YEARS OR OVER FOR THE WORLD, DEVELOPMENT GROUPS, REGIONS AND INCOME GROUPS, 2000, 2015, 2030 AND 2050</caption><thead><tr><th rowspan="2"></th><th colspan="4">Percentage aged 60 years or over</th><th colspan="2">Percentage point change</th></tr><tr><th>2000</th><th>2015</th><th>2030</th><th>2050</th><th>2000-2015</th><th>2015-2030</th></tr></thead><tbody><tr><td>World</td><td>9.9</td><td>12.3</td><td>16.5</td><td>21.5</td><td>2.3</td><td>4.2</td></tr><tr><td><strong>Development groups</strong></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>More developed regions</td><td>19.5</td><td>23.9</td><td>29.2</td><td>32.8</td><td>4.4</td><td>5.3</td></tr><tr><td>Less developed regions</td><td>7.6</td><td>9.9</td><td>14.2</td><td>19.8</td><td>2.3</td><td>4.4</td></tr><tr><td>Other less developed countries</td><td>8.0</td><td>10.7</td><td>15.9</td><td>22.7</td><td>2.7</td><td>5.2</td></tr><tr><td>Least developed countries</td><td>5.1</td><td>5.5</td><td>6.7</td><td>9.8</td><td>0.4</td><td>1.2</td></tr><tr><td><strong>Regions</strong></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Africa</td><td>5.2</td><td>5.4</td><td>6.3</td><td>8.9</td><td>0.2</td><td>0.8</td></tr><tr><td>Asia</td><td>8.6</td><td>11.6</td><td>17.2</td><td>24.6</td><td>3.0</td><td>5.6</td></tr><tr><td>Europe</td><td>20.3</td><td>23.9</td><td>29.6</td><td>34.2</td><td>3.6</td><td>5.7</td></tr><tr><td>Latin America and the Caribbean</td><td>8.1</td><td>11.2</td><td>16.8</td><td>25.5</td><td>3.1</td><td>5.6</td></tr><tr><td>Oceania</td><td>13.4</td><td>16.5</td><td>20.2</td><td>23.3</td><td>3.1</td><td>3.7</td></tr><tr><td>Northern America</td><td>16.2</td><td>20.8</td><td>26.4</td><td>28.3</td><td>4.6</td><td>5.6</td></tr><tr><td><strong>Income groups</strong></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>High-income countries</td><td>18.0</td><td>22.1</td><td>27.7</td><td>31.9</td><td>4.1</td><td>5.6</td></tr><tr><td>Upper-middle-income countries</td><td>9.2</td><td>13.4</td><td>21.2</td><td>30.5</td><td>4.2</td><td>7.8</td></tr><tr><td>Lower-middle-income countries</td><td>6.9</td><td>8.1</td><td>11.2</td><td>16.5</td><td>1.2</td><td>3.0</td></tr><tr><td>Low-income countries</td><td>5.0</td><td>5.2</td><td>5.8</td><td>8.3</td><td>0.2</td><td>0.7</td></tr></tbody></table>

<table><thead><tr><th rowspan="2"></th><th colspan="4">Percentage aged 80 years or over</th><th colspan="2">Percentage point change</th></tr><tr><th>2000</th><th>2015</th><th>2030</th><th>2050</th><th>2000-2015</th><th>2015-2030</th></tr></thead><tbody><tr><td>World</td><td>1.2</td><td>1.7</td><td>2.4</td><td>4.5</td><td>0.5</td><td>0.7</td></tr><tr><td><strong>Development groups</strong></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>More developed regions</td><td>3.1</td><td>4.7</td><td>6.6</td><td>9.9</td><td>1.7</td><td>1.9</td></tr><tr><td>Less developed regions</td><td>0.7</td><td>1.1</td><td>1.6</td><td>3.6</td><td>0.4</td><td>0.5</td></tr><tr><td>Other less developed countries</td><td>0.7</td><td>1.2</td><td>1.8</td><td>4.4</td><td>0.4</td><td>0.6</td></tr><tr><td>Least developed countries</td><td>0.4</td><td>0.5</td><td>0.6</td><td>1.1</td><td>0.1</td><td>0.1</td></tr><tr><td><strong>Regions</strong></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Africa</td><td>0.4</td><td>0.5</td><td>0.6</td><td>0.9</td><td>0.1</td><td>0.1</td></tr><tr><td>Asia</td><td>0.8</td><td>1.4</td><td>2.1</td><td>4.9</td><td>0.5</td><td>0.7</td></tr><tr><td>Europe</td><td>2.9</td><td>4.7</td><td>6.3</td><td>10.1</td><td>1.8</td><td>1.6</td></tr><tr><td>Latin America and the Caribbean</td><td>1.0</td><td>1.6</td><td>2.6</td><td>5.7</td><td>0.7</td><td>1.0</td></tr><tr><td>Oceania</td><td>2.2</td><td>2.9</td><td>4.3</td><td>6.4</td><td>0.7</td><td>1.4</td></tr><tr><td>Northern America</td><td>3.2</td><td>3.8</td><td>5.6</td><td>8.6</td><td>0.6</td><td>1.7</td></tr><tr><td><strong>Income groups</strong></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>High-income countries</td><td>2.9</td><td>4.3</td><td>6.2</td><td>9.6</td><td>1.5</td><td>1.8</td></tr><tr><td>Upper-middle-income countries</td><td>0.9</td><td>1.6</td><td>2.6</td><td>7.0</td><td>0.7</td><td>1.0</td></tr><tr><td>Lower-middle-income countries</td><td>0.6</td><td>0.8</td><td>1.1</td><td>2.3</td><td>0.3</td><td>0.3</td></tr><tr><td>Low-income countries</td><td>0.3</td><td>0.4</td><td>0.5</td><td>0.8</td><td>0.1</td><td>0.1</td></tr></tbody></table>

Data source: United Nations (2015). World Population Prospects: The 2015 Revision.
These shifts over time in the relative sizes of the various age groups have resulted in increases in the proportion of the population at older ages. At the global level, the percentage of older persons increased from close to 10 per cent in 2000 to over 12 per cent in 2015, when one in every eight people worldwide was aged 60 years or over (table II.2). The proportion of older persons globally is projected to continue to increase to more than 16 per cent in 2030 and over 21 per cent in 2050. Thus, by the middle of the twenty-first century, around one in every five people globally will be aged 60 years or over.

Older persons already constitute a large share of the population in the more developed regions. In 2015, close to one in four people living in developed regions was aged 60 years or over, and it is projected to continue to rise such that, in 2050, older persons will account for one in three people in the developed regions. People aged 60 years or over comprised nearly 10 per cent of the population in developing regions in 2015, and that share is projected to increase to 14 per cent in 2030 and to 20 per cent in 2050. Among the least developed countries, older persons accounted for a relatively small fraction of the total population—5.5 per cent in 2015—but the share of older persons in the least developed countries is also projected to increase in the coming decades, reaching nearly 10 per cent in 2050.

**High-income countries tend to be the most aged.**

Older persons comprised 22 per cent of the population of high-income countries in 2015, 13 per cent of upper-middle-income countries, 8 per cent of lower-middle-income countries and 5 per cent of low-income countries. Figure II.15 plots the percentage of the population aged 60 years or over in 2015 against each country's gross national income per capita in 2014 for countries with at least 90,000 inhabitants in 2015 and for which a GNI estimate was available. The size of the bubbles is proportional to the size of the population aged 60 years or over in 2015.

**Japan is home to the world's most aged population: 33 per cent were aged 60 years or over in 2015.**

Japan is followed by Germany (28 per cent aged 60 years or over in 2015), Italy (28 per cent) and Finland (27 per cent).<fnref n="6" /> Of the 62 high-income countries or areas with total population greater than 90,000 in 2015, half had relatively aged populations in 2015, with 20 per cent of the population aged 60 years or over. The proportion of older persons also exceeded 20 per cent among several upper-middle-income European countries, such as Bulgaria (27 per cent aged 60 years or over in 2015) and Romania (22 per cent). Comparatively young age structures prevailed among countries at the lower end of the income distribution: in every low-income country and 85 per cent of lower-middle-income countries in 2015, less than 10 per cent of the population was aged 60 years or over.

**By 2030 many middle-income countries will have aged considerably.**

Within the next 15 years, several upper-middle-income countries are projected to become as aged as many of today's high-income countries. Between 2015 and 2030, the share of population

<footnote n="6">⁶ Of the 201 countries or areas with at least 90,000 inhabitants in 2015.</footnote>
<figure><img src="image_20.png" /><figcaption>**Figure II.15.** Percentage aged 60 years or over in 2015 versus gross national income per capita in 2014</figcaption></figure>

*Data source: United Nations (2015). World Population Prospects: The 2015 Revision.*

<figure><img src="image_21.png" /><figcaption>**Figure II.16.** Percentage aged 60 years or over projected in 2030 versus gross national income per capita in 2014</figcaption></figure>

*Data source: United Nations (2015). World Population Prospects: The 2015 Revision.*
aged 60 years or over is projected to increase from 15 per cent to 24 per cent in China, from 20 per cent to 32 per cent in Cuba, and from 16 per cent to 27 per cent in Thailand (figure II.16). Some lower-middle-income countries are projected to age rapidly as well. For example, the proportion aged 60 years or over is projected to increase from 13 per cent in 2015 to 20 per cent in 2030 in Sri Lanka; from 10 to 18 per cent in Viet Nam; and from 8 to 14 per cent in Morocco.

The population ageing process is much slower in low-income countries: in 89 per cent of low-income countries and 62 per cent of lower-middle-income countries, the share of older persons is projected to remain below 10 per cent through 2030.

In 2000, of the world's ten most aged populations all but one (Japan) were located in Europe and the share of the population aged 60 years or over had not yet reached 25 per cent in any country. In 2015 the share of older persons exceeded 25 per cent in all ten of the most aged countries and, by 2030, older persons will comprise more than 32 per cent of the population in each of the ten most aged countries or areas (table II.3). Europe is expected to account for 7 of the 10 most aged countries in 2030. Projections indicate that in 2030, Martinique will be home to the world's most aged population, with 38.5 per cent aged 60 years or over. All three major demographic processes have contributed to rapid population ageing in Martinique: sharp reductions in total fertility, from 5.7 children per woman in the 1950s to 2.1 children per woman in the 1980s; increasing longevity, with life expectancy at birth having risen from 56 years in 2010-2015 to around 81 years in 2010-2015; as well as net emigration of young people.

<table><caption>TABLE II.3. TEN COUNTRIES OR AREAS WITH THE MOST AGED POPULATIONS, 2000, 2015 AND 2030*
(SEE ANNEX TABLE A.III.4 FOR FULL LIST OF COUNTRIES OR AREAS RANKED ACCORDING TO THE PERCENTAGE AGED 60 OR OVER)</caption><thead><tr><th rowspan="2">Rank</th><th colspan="2">2000</th><th colspan="2">2015</th><th colspan="2">2030</th></tr><tr><th>Country or area</th><th>Percentage aged 60 years or over</th><th>Country or area</th><th>Percentage aged 60 years or over</th><th>Country or area</th><th>Percentage aged 60 years or over</th></tr></thead><tbody><tr><td>1</td><td>Italy</td><td>24.1</td><td>Japan</td><td>33.1</td><td>Martinique</td><td>38.5</td></tr><tr><td>2</td><td>Japan</td><td>23.3</td><td>Italy</td><td>28.6</td><td>Japan</td><td>37.3</td></tr><tr><td>3</td><td>Germany</td><td>23.1</td><td>Germany</td><td>27.6</td><td>Italy</td><td>36.6</td></tr><tr><td>4</td><td>Greece</td><td>22.8</td><td>Finland</td><td>27.2</td><td>Germany</td><td>36.1</td></tr><tr><td>5</td><td>Sweden</td><td>22.2</td><td>Portugal</td><td>27.1</td><td>Portugal</td><td>34.7</td></tr><tr><td>6</td><td>Bulgaria</td><td>22.2</td><td>Greece</td><td>27.0</td><td>China, Hong Kong SAR</td><td>33.6</td></tr><tr><td>7</td><td>Belgium</td><td>22.0</td><td>Bulgaria</td><td>26.9</td><td>Spain</td><td>33.5</td></tr><tr><td>8</td><td>Croatia</td><td>21.8</td><td>Martinique</td><td>26.2</td><td>Greece</td><td>33.2</td></tr><tr><td>9</td><td>Portugal</td><td>21.7</td><td>Croatia</td><td>25.9</td><td>Slovenia</td><td>32.7</td></tr><tr><td>10</td><td>Spain</td><td>21.4</td><td>Latvia</td><td>25.7</td><td>Austria</td><td>32.4</td></tr></tbody></table>

Data source: United Nations (2015). *World Population Prospects: The 2015 Revision*.

* Of 201 countries or areas with at least 90,000 inhabitants in 2015.

## The pace of world population ageing is accelerating.

Over the 15 years between 2000 and 2015, the proportion of the global population that was aged 60 years or over increased by 2.3 percentage points, from 9.9 per cent to 12.3 per cent
(table II.2; figure II.17). Projections indicate that over the next 15 years the proportion aged 60 years or over globally will increase by 4.2 percentage points reaching 16.5 per cent in 2030. Between 2000 and 2015, the pace of population ageing was fastest in Northern America (4.6 percentage point increase) and Europe (3.6 percentage points). The pace of population ageing is projected to accelerate in all six regions. Between 2015 and 2030 projected increases in the proportion aged 60 years or over are nearly identical for Asia (5.6 percentage point increase), Europe (5.7), Latin America and the Caribbean (5.6) and Northern America (5.6).

<figure><img src="image_22.png" /><figcaption>**Figure II.17.** Percentage point change in the proportion aged 60 years or over for the world and regions, 2000-2015 and 2015-2030</figcaption></figure>

Data source: United Nations (2015). *World Population Prospects: The 2015 Revision*.

By 2050, older persons are projected to account for 34 per cent of the population of Europe, 28 per cent of Northern America, 26 per cent of Latin America and the Caribbean, 25 per cent of Asia, 23 per cent of Oceania, and 9 per cent of Africa (figure II.18).

In many developing countries, population ageing is taking place much more rapidly than it did in the countries that developed earlier. For example, it took France 115 years, Sweden 85 years, Australia 73 years, the United States 69 years and the United Kingdom and Spain 45 years each for the proportion of the population aged 60 years or over to increase from 7 to 14 per cent (Kinsella and Gist, 1995). In contrast, it has taken China only 34 years and Thailand only 23 years to experience the same change in the share of older persons. Projections indicate that for Brazil, it will take just 25 years for the percentage of older persons to rise from 7 to 14 per cent and the same change in the proportion aged 60 years or over will take just 22 years in Colombia.
Thus, today's developing countries have to adapt much more quickly to population ageing, and often at much lower levels of national income compared to the past experience of many of the countries that developed earlier.

<figure><img src="image_23.png" /><figcaption>Figure II.18. Percentage of the population aged 60 years or over for the world and regions, 1980-2050</figcaption></figure>

Data source: United Nations (2015). *World Population Prospects: The 2015 Revision*.

The pace of population ageing observed at the country level illustrates just how fast the age structures are shifting in many parts of the world. Table II.4 lists the ten countries with the largest percentage point changes in the share of older persons in 2000-2015 and projected for 2015-2030. Of countries or areas with 90,000 inhabitants or more in 2015, the United States Virgin Islands experienced the fastest rise in the proportion of the population aged 60 years or over, with an increase of nearly 11 percentage points between 2000 and 2015. Japan was the next fastest (a 9.9 percentage point increase), followed by Malta (9.3), Finland (7.3) and the Republic of Korea (7.2). Over the coming 15 years, the most rapidly ageing countries are projected to experience increases in the proportion of older persons that are considerably faster than those observed over the previous 15-year period. Cuba and the Republic of Korea, two countries that have experienced both sharp declines in fertility and substantial gains in longevity since the mid-twentieth century, are projected to see the largest change in the proportion aged 60 years or over between 2015 and 2030, with increases of nearly 13 percentage points. An additional seven countries or areas are also projected to experience increases in the proportion of older persons of more than 10 percentage points over the next 15 years.
<caption>TABLE II.4. TEN COUNTRIES OR AREAS WITH THE LARGEST PERCENTAGE POINT CHANGES IN THE PROPORTION OF THE POPULATION AGED 60 YEARS OR OVER, 2000-2015 AND 2015-2030
(SEE ANNEX TABLE A.III.5 FOR FULL LIST OF COUNTRIES OR AREAS RANKED ACCORDING TO THE PERCENTAGE POINT CHANGE IN THE PROPORTION AGED 60 OR OVER)*</caption>

<table><thead><tr><th>Rank</th><th>Country or area</th><th>Percentage point change between 2000 and 2015</th><th>Country or area</th><th>Percentage point change between 2015 and 2030</th></tr></thead><tbody><tr><td>1</td><td>United States Virgin Islands</td><td>10.9</td><td>Cuba</td><td>12.8</td></tr><tr><td>2</td><td>Japan</td><td>9.9</td><td>Republic of Korea</td><td>12.7</td></tr><tr><td>3</td><td>Malta</td><td>9.3</td><td>China, Hong Kong SAR</td><td>12.3</td></tr><tr><td>4</td><td>Finland</td><td>7.3</td><td>China, Taiwan Province of China</td><td>12.1</td></tr><tr><td>5</td><td>Republic of Korea</td><td>7.2</td><td>Curaçao</td><td>11.7</td></tr><tr><td>6</td><td>Aruba</td><td>7.0</td><td>China, Macao SAR</td><td>11.4</td></tr><tr><td>7</td><td>Martinique</td><td>6.9</td><td>Thailand</td><td>11.2</td></tr><tr><td>8</td><td>China, Hong Kong SAR</td><td>6.9</td><td>Martinique</td><td>11.0</td></tr><tr><td>9</td><td>China, Taiwan Province of China</td><td>6.7</td><td>Brunei Darussalam</td><td>11.0</td></tr><tr><td>10</td><td>Curaçao</td><td>6.6</td><td>Singapore</td><td>9.9</td></tr></tbody></table>

Data source: United Nations (2015). *World Population Prospects: The 2015 Revision*.

* Of 201 countries or areas with at least 90,000 inhabitants in 2015.

In 2050, nearly half of the world's population will live in countries or areas where at least 20 per cent of the population is aged 60 years or over, and one in four people will live in countries or areas where older persons account for more than 30 per cent of the population.

In 2000, the share of the population aged 60 years or over exceeded 20 per cent in only 23 countries or areas<fnref n="7" /> and these contained just 9 per cent of the global population. Projections indicate that the number of countries or areas where at least 20 per cent of the population is aged 60 years or over is projected to grow from a minority of 53 in 2015 to a large majority of 145 in 2050, and the share of the world's people living in such countries or areas is projected to increase from 17 per cent to 44 per cent. In 74 countries or areas, older persons are projected to make up at least 30 per cent of the population in 2050, up from just 3 countries or areas<fnref n="8" /> in 2015. Conversely, the number of countries with very young population age structures is shrinking over time. While in 2015 there were 37 countries or areas where less than 5 per cent of the population were aged 60 years or over, by 2050 the share of older persons is projected to be below 5 per cent in only one country (Niger).

<footnote n="7">⁷ Of the 233 countries or areas for which the United Nations estimates and projects total population.</footnote>

<footnote n="8">⁸ The Holy See, Japan and Monaco.</footnote>
<figure><img src="image_24.png" /><figcaption>**Figure II.19.**
Maps of percentage of population aged 60 years or over in 2000, 2015 and 2050</figcaption></figure>

*Data source:* United Nations (2015). *World Population Prospects: The 2015 Revision.*

*Note:* The boundaries and names shown and the designations used on this map do not imply official endorsement or acceptance by the United Nations. Dotted line represents approximately the Line of Control in Jammu and Kashmir agreed upon by India and Pakistan. The final status of Jammu and Kashmir has not yet been agreed upon by the parties. Final boundary between the Republic of Sudan and the Republic of South Sudan has not yet been determined.
## D. DEPENDENCY AND SUPPORT RATIOS

Population ageing, which is driven by both declining fertility and increasing longevity, implies that successive cohorts can expect to live longer and have fewer adult children as potential sources of support in their old age. This section discusses trends in various descriptive measures of population ageing that are used often to examine the implications of shifting population age structures for intergenerational support systems.

The total dependency ratio is a commonly used measure of potential support needs. It is based on the notion of childhood and old age as periods of dependency during which persons tend to rely upon the working-age population for financial support, which may be provided directly through family transfers, or indicrectly through public transfer programmes. The total dependency ratio is defined here as the ratio of the number of children and young people under age 20 plus the number of persons aged 65 years or over, to the number of persons aged 20 to 64 years. The ratio provides an indication of how many dependents need to be supported by each person of working age, on average. The actual ages of dependency vary considerably from country to country and from one person to another, since factors like the pursuit of higher education or youth unemployment often prolong the dependent period beyond age 20, while personal preferences, as well as health and financial considerations, influence the age at which people retire from the workforce. Despite these limitations, the choice of the age range 20 to 64 years for the working ages serves here as a starting point to facilitate comparisons of age structures across populations and over time.

**The global total dependency ratio has fallen to a historical minimum and is set to rise in the post-2015 period.**

At the global level, the total dependency ratio has fallen to a historical minimum in 2015 (figure II.20). From a peak of approximately 112 “dependents” per 100 working-age persons in the early-1970s, the total dependency ratio declined steadily in response to sustained reductions in global fertility, to reach 74 dependents per 100 working-age persons in 2015. The total dependency ratio is projected to increase gradually over the coming decades together with the growing proportion of older persons. By 2030, there will be 76 people in the dependent ages per 100 working-age people, and by 2050 the global total dependency ratio is projected to rise to 79 dependents per 100 working-age persons. A rising ratio indicates that there will be slightly more dependents to be supported by each person of working ages.

**The total dependency ratio is projected to increase in all regions except Africa.**

The total dependency ratio is projected to rise the fastest in regions that have already seen substantial increases in the proportion of older persons, such as Europe and Northern America. As a result of several decades of comparatively low fertility, the total dependency ratios in Europe and Northern America were lower than in the other regions in the second half of the twentieth century. In 2015, the total dependency ratios in these two regions were 62 and 67 dependents per 100 working-age persons, respectively, which were similar to that in Asia at 66 dependents per 100 working-age persons, and slightly lower than in Latin America and the Caribbean at 73 dependents per 100 working-age persons. By 2050, the total dependency ratio is projected to increase to 91 in Europe and to 84 in Northern America, overtaking all other
regions. The increasing proportions of older persons in Asia and Latin America and the Caribbean will also boost future increases in the total dependency ratio, which, in 2050, is projected to reach 73 dependents per 100 working-age people in Asia and 74 per 100 in Latin America and the Caribbean in 2050.

<figure><img src="image_25.png" /><figcaption>Figure II.20.
Total dependency ratio for the world and regions, 1950-2050</figcaption></figure>

Data source: United Nations (2015). *World Population Prospects: The 2015 Revision.*

Fertility decline began more recently in Africa than in the other regions, and thus the proportion of children is starting to fall and the share of working-age persons is beginning to increase, while the proportion of older persons in the population remains fairly small. As a result, the total dependency ratio in Africa is falling gradually, and that decline is projected to continue into the second half of the twenty-first century. The dependency ratio in Africa fell from its peak of 140 dependents per 100 working-age persons in the mid-1980s to 121 dependents per 100 working-age persons in 2015, and is projected to continue to decline to 91 dependents per 100 working-age persons in 2050.

**The global increase in the total dependency ratio will be driven by a growing share of older persons.**

Changes in the total dependency ratio are driven by changes in the proportions of children and of older persons. Figure II.21 illustrates the distribution of people in the dependent ages in the world, distinguishing children and young people under 20 years of age and older persons aged 65 years or over. In 1950, the vast majority of dependents worldwide were children, while older persons accounted for just 10 per cent of the global dependent-age population. Since the mid-1960s, however, the share of older persons among the world's dependents has grown, reaching 20 per cent in 2015, and is expected to continue to grow steadily into the future. Projections indicate that in 2050 older persons will account for 36 per cent of people in the dependent ages worldwide.
<figure><img src="image_26.png" /><figcaption>**Figure II.21.**
Children and young people aged under 20 years and older persons aged 65 years or over as a percentage of the global population in the dependent ages, 1950-2100</figcaption></figure>

*Data source: United Nations (2015). World Population Prospects: The 2015 Revision.*

The economic support ratio takes into account the age patterns of production and consumption to describe the number of effective workers in a population relative to the number of effective consumers.

Rather than assuming a status of “dependency” at given ages, a better way to assess the degree of dependency in a population is to consider the age patterns of production and consumption. Age patterns of production reflect labour earnings and represent the economic contribution of individuals at each age to their own sustenance and to the support of others. In turn, the age patterns of consumption provide a measure of the population’s needs at each age. While these economic factors are at best implicit in the conventional demographic dependency ratios, the economic support ratio makes them explicit, and considers them together with the population age structure.

The economic support ratio is defined as the effective number of workers divided by the effective number of consumers in a given population (Lee and Mason, 2011; United Nations, 2013). The effective number of workers is obtained by the product of the labour income at each age by the population in the corresponding age group, summed over all ages. Age variations in labour force participation, hours worked, unemployment and wages are taken into account and are reflected in the country-specific labour income profile. Similarly, the effective number of consumers is calculated as the sum over all ages of the product of consumption at each age by the population in that age group.
Figure II.22 shows the average annual changes in the economic support ratio in different countries, estimated for the period 1980-2015 and projected for 2015-2050, based on information on the labour income and consumption age profiles for recent years compiled in the National Transfer Accounts (NTA) database,<fnref n="9" /> together with United Nations estimates and projections of population by age and sex. A rising economic support ratio, reflected in a positive growth rate in figure II.22, means that, during the reference time period, each worker is supporting fewer consumers, on average. This situation is favourable for economic development, since it frees up resources that can be used to increase per capita consumption, savings and investment, thereby fuelling further economic growth (Lee and Mason, 2011). Conversely, a declining support ratio, reflected in a negative growth rate, means that there are fewer equivalent producers to support each equivalent consumer, which constrains the present standard of living and future economic growth.

**Countries that underwent a rapid fertility decline between the 1970s and 1990s benefitted from increasing economic support ratios during the period 1980-2015.**

Growth of the economic support ratio over 1980-2015 was particularly high in several Asian countries, such as China, the Republic of Korea, Thailand and Viet Nam, where the average annual growth rate ranged from 0.7 to 0.9 per cent (figure II.22, top chart). The rate of growth of the economic support ratio growth during that period was still significant in Brazil, Colombia and South Africa, ranging from 0.5 to 0.7 per cent per year. In contrast, the growth rate was comparatively modest in high-income countries that had already achieved low fertility: Australia, France, Italy, the United Kingdom and the United States show growth rates of the economic support ratio in the range of 0.1 to 0.2 per cent annually over 1980-2015. In countries with very low fertility, such as Japan, the economic support ratio actually declined during that period.

**Increasing economic support ratios are projected to contribute to future economic growth in a number of middle-income and low-income countries.**

Economic support ratios, projected under the assumption that age patterns of production and consumption remain unchanged over 2015-2050, illustrate at the potential influence of demographic changes on economic growth<fnref n="10" /> (figure II.22, bottom panel). For example, In India and Indonesia, the economic support ratio is projected to continue growing over the period 2015-2050, boosting economic growth by about 0.2 per cent per year. In Nigeria and Kenya, the economic support ratios are expected to increase even faster, resulting in an addition to economic growth of 0.3 per cent per year over the period 2015-2050, on average.<fnref n="11" />

<footnote n="9">⁹ http://www.ntaccounts.org/.</footnote>

<footnote n="10">¹⁰ These results are obtained by multiplying the latest available age-specific patterns of production of consumption (see footnote 8), by the population by age of the medium projection variant of the *World Population Prospects: The 2015 Revision* (United Nations, 2015).</footnote>

<footnote n="11">¹¹ If fertility declines faster than anticipated in the medium variant, if investment in human and physical capital increase, or labour markets improve, then the actual future growth rate of the economic support ratio would be higher than shown in figure II.22.</footnote>
<figure><img src="image_27.png" /><figcaption>Figure II.22. Average annual change in the economic support ratio, selected countries, 1980-2015 and 2015-2050</figcaption></figure>

Data source: National Transfer Accounts database (http://www.ntaccounts.org/), accessed 1 September 2015.
Many high-income and upper-middle-income countries will experience declining economic support ratios, especially where populations are already aged.

Other things being equal, the declining economic support ratios projected between 2015 and 2050 would contribute to dampen economic growth in Japan and in Spain, for example, by about 0.5 per cent per year and 0.8 per cent per year, respectively. In the United States, where the ageing process is less advanced due to somewhat higher fertility and mortality than in other high-income countries as well as to significant inflow of migrants, the projected changes in the economic support ratio is smaller, of less than 0.3 per cent per year. The support ratios in Argentina, Colombia, Mexico and Uruguay are projected to decline slightly, with ensuing lesser effects on economic growth, of only -0.05 per cent per year during 2015-2050.

In many upper-middle-income countries, the share of the working-age population is presently reaching a peak. In the coming decades, these countries are expected to experience accelerated population ageing and declining economic support ratios, reaching levels similar to those of the high-income countries today. The decline in the support ratio is projected to be more pronounced in countries with more aged populations, such as China, Germany, Italy, the Republic of Korea, Spain, Slovenia and Thailand, where the economic support ratios are projected to decline by more than 0.5 per cent per year over 2015-2050.
<figure><img src="image_28.png" /></figure>
### III. Demographic drivers of population ageing

The size and age composition of a population are determined jointly by three demographic processes: fertility, mortality and migration. Fertility levels and trends determine the size of each birth cohort; while mortality levels and trends determine what proportion of those cohorts eventually survive to old age. Age patterns of immigration and emigration also influence the age distribution of the population, although to a lesser extent than fertility and mortality in most countries. This chapter describes the relationships between the three main demographic processes and population ageing, drawing primarily upon United Nations population estimates and projections from *World Population Prospects: the 2015 Revision*.

#### A. FERTILITY AND MORTALITY AS DETERMINANTS OF TRENDS IN THE NUMBERS OF OLDER PERSONS

The present growth rate of the population of older persons is a function of the levels of fertility prevailing some 60 years ago when today's new cohorts of older persons were born, together with the likelihood that members of those birth cohorts survived to older ages. Figure III.1 shows the growth rate of the population aged 60 or over in 2010-2015 versus the total fertility rate (expressed as the average number of children per woman) 60 years earlier, in 1950-1955, for countries or areas with at least 500,000 residents aged 60 years or older in 2015.<fnref n="12" />

**In general, countries that had high fertility 60 years ago saw faster growth in the number of older persons during 2010-2015.**

In the Philippines, for example, the total fertility rate was 7.4 children per woman in 1950-1955, and today, the number of older people (aged 60 years or over) is growing rapidly, at an average 3.6 per cent per year in 2010-2015. By contrast, in Italy, total fertility was only 2.4 children per woman in 1950-1955, and today's older population is growing much slower than in the Philippines, at an average annual rate of 1.4 per cent during 2010-2015. Because fertility rates in the mid-century were high—above five children per woman—in many parts of Africa, Asia and Latin America and the Caribbean, the growth rates of the older populations in those regions are significantly higher than in Europe, where fertility in 1950-1955 had already fallen below three children per woman in many countries.

The association between past fertility rates and the present rates of growth of the numbers of older persons across countries shown in Figure III.1 is tempered by variation in mortality risks across countries with similar levels of fertility. For example, in Mexico, where total fertility was 6.8 children per woman in 1950-1955, the average annual growth rate of the population of older persons in 2010-2015 was 4.1 per cent, but in Côte d'Ivoire, where total fertility at 6.8 children per woman in 1950-1955 was similar to that in Mexico, the growth rate of the older population in 2010-2015 was only around half that in Mexico, at 2.3 per cent. The difference can be explained largely by the disparate mortality risks between the two countries: people born in Mexico during

<footnote n="12">¹² Looking at fertility levels some 60-80 or even 90 years prior, would offer a more complete illustration of how past fertility drives the pace of growth of the older population. However, given that there are no internationally comparable time series of fertility estimates before 1950, the period 60 years in the past is used as a first approximation for this analysis.</footnote>
the mid-twentieth century were twice as likely to survive to old age as those born in Côte d'Ivoire. More specifically, an estimated 66 per cent of babies born in Mexico in 1950-1955 survived to celebrate their 60th birthdays in 2010-2015, compared to just 33 per cent of their peers born in Côte d'Ivoire (figure III.2).<fnref n="13" /> Persons born in Côte d'Ivoire at the mid-century were twice as likely as their counterparts in Mexico to die before age five and excess mortality associated with armed conflict and the HIV/AIDS epidemic contributed the lower probabilities of survival to older ages there as well.

A similar comparison can be made for China and Nigeria. While total fertility rates in both China and Nigeria were similar at the mid-century at 6.1 and 6.4 children per woman, respectively, the older population in China in 2010-2015 was growing nearly twice as fast as in Nigeria (4.6 per cent versus 2.4 per cent per year) owing in part to the greater survival to old age of people in China. An estimated 66 per cent of the people born in China in 1950-1955 survived to their 60th birthdays compared to 37 per cent of those born in Nigeria.

<figure><img src="image_29.png" /><figcaption>**Figure III.1.** Average annual percentage change in the population aged 60 years or over in 2010-2015 and total fertility in 1950-1955 *</figcaption></figure>

*Data source:* United Nations (2015). World Population Prospects: The 2015 Revision.

* Countries or areas with at least 500,000 residents aged 60 or over in 2015.

<footnote n="13">¹³ The probability that members of the 1950-1955 birth cohort survive to age 60 is estimated using cohort life tables constructed of the quinquennial estimates of age-specific mortality from the *2015 Revision of World Population Prospects*.</footnote>
<figure><img src="image_30.png" /><figcaption>**Figure III.2.** Average annual percentage change in the population aged 60 years or over in 2010-2015 and probability of survival to age 60 among the 1950-1955 birth cohort*2</figcaption></figure>

Data source: United Nations (2015). *World Population Prospects: The 2015 Revision*.

* Countries or areas with at least 500,000 residents aged 60 or over in 2015.

Table III.1 lists the current size and growth rate of the population of older persons for the world and six regions, as well as the fertility rates around the time that today's 60-year-olds were born and their survival probabilities to age 60.² In 2010-2015, the population of older persons was growing most rapidly in Asia and Latin America and the Caribbean, at an average 3.8 per cent per year. Both of these regions were characterized by high fertility in 1950-1955, at 5.8 and 5.9 children per woman, respectively. Moreover, a majority of the 1950-1955 birth cohorts survived to old age: 59 per cent of those born in Asia during 1950-1955 were still alive at age 60, as were 65 per cent of those born in Latin America and the Caribbean.

The older populations of Northern America and Oceania were also growing rapidly during 2010-2015, by 3.1 per cent annually in 2010-2015, despite having had much lower fertility compared to Latin America and the Caribbean and Asia at the mid-century (3.4 and 3.8 children per woman, respectively). In both Northern America and Oceania, growth of the older population has been bolstered by high probabilities of survival to older ages: close to 85 per cent of the 1950-1955 birth cohort in Northern America lived to at least age 60, as did 78 per cent of their peers in Oceania.

The pace of growth of the older population in Africa, at 3.0 per cent per year during 2010-2015, was similar to that in Northern America and Oceania, although the probability of survival to age 60 years in Africa was much lower, with just 42 per cent of those born in 1950-1955
surviving to their 60th birthdays. In this instance, very high fertility, at 6.6 children per woman in 1950-1955, has compensated for lower survival to old age to promote rapid growth of the population of older persons in Africa.

While Europe is home to the world's most aged population in 2015, the pace of growth of the older population in Europe was the slowest of the six regions during 2010-2015, at 1.7 per cent per year on average, owing to already low fertility in Europe in 1950-1955 at 2.7 children per woman, and a lower probability of survival to older ages relative to Northern America, with 76 per cent of Europe's 1950-1955 birth cohort alive at age 60 years.

<table><caption>TABLE III.1. OLDER POPULATION SIZE AND GROWTH RATE, AND PAST FERTILITY AND MORTALITY LEVELS FOR THE WORLD AND REGIONS</caption><thead><tr><th></th><th>Population aged 60 years or over in 2015 (thousands)</th><th>Average annual rate of change of the population aged 60 years or over in 2010-2015 (percentage)</th><th>Total fertility in 1950-1955 (children per woman)</th><th>Percentage of 1950-1955 birth cohort surviving to age 60<sup>2</sup></th></tr></thead><tbody><tr><td>World</td><td>900 906</td><td>3.3</td><td>5.0</td><td>61.2</td></tr><tr><td>Africa</td><td>64 447</td><td>3.0</td><td>6.6</td><td>42.3</td></tr><tr><td>Asia</td><td>507 954</td><td>3.8</td><td>5.8</td><td>59.4</td></tr><tr><td>Europe</td><td>176 513</td><td>1.7</td><td>2.7</td><td>75.6</td></tr><tr><td>Latin America and the Caribbean</td><td>70 922</td><td>3.8</td><td>5.9</td><td>65.0</td></tr><tr><td>Northern America</td><td>74 589</td><td>3.1</td><td>3.4</td><td>84.7</td></tr><tr><td>Oceania</td><td>6 481</td><td>3.1</td><td>3.8</td><td>78.3</td></tr></tbody></table>

Data source: United Nations (2015). *World Population Prospects: The 2015 Revision*.

**Global trends in the growth rate of the older population reveal the powerful influence of major historical events in shaping the age composition of the world's population.**

Figure III.3 plots the average annual rates of change of the global population aged 60 years or over and aged 80 years or over, respectively, by 5-year period, estimated since 1950 and projected until 2050. The sharp fluctuations observed in the growth rate of the population of older persons point to the historical events that produced significant demographic shocks during the early- to mid-twentieth century. For example, the sharp decline in the growth rate of the global population aged 80 years or over in the late 1990s marks the period during which the cohorts born around World War I and affected by the 1918 influenza pandemic would have reached their 80s. Similarly, the decline in the growth rate of the global population aged 60 years or over in 2000-2005 marks the period during which the cohorts born during the period of lower fertility surrounding World War II would have turned 60 years old; the projected decline in the growth rate of the population aged 80 years or over in 2020-2025 marks when they would have turned 80 years old.
<figure><img src="image_31.png" /><figcaption>**Figure III.3.** Average annual rate of change of the global population aged 60 years or over and aged 80 years or over, 1980-2050</figcaption></figure>

*Data source: United Nations (2015). World Population Prospects: The 2015 Revision.*

Conversely, the peaks in the growth rate shown for the populations aged 60 years or over in 2010-2015 and aged 80 years or over in 2030-2035 mark the periods during which those born during the post-World War II baby boom reach older ages. The growth rate of the global population aged 60 years or over climbed from a low of 2.0 per cent per year during 2000-2005, when the cohorts born during World War II were reaching age 60 years, to a peak of close to 3.3 per cent per year in 2010-2015, when the baby boomers were reaching age 60. For the global population aged 80 years or over, the growth rate is projected to rise from just over 2.5 per cent per year in 2020-2025, when the World War II cohorts turn 80 years old, to 4.6 per cent per year when the baby boomers reach age 80 years.

Just as current population ageing has been determined by historical levels and changes in fertility and mortality, the coming trends with respect to population ageing can be understood as having grown out of the history of fertility and mortality shifts that have taken place over the last century. While the fluctuations evident in figure III.3 point to extreme examples of the historical influences of demographic shocks at the global level, shifts in fertility and mortality have played out differently across the world's regions. Consequently, the global trends in the numbers of older persons can also be understood as an aggregation of heterogeneous regional demographic trends over time. The following two sections of this chapter describe the recent and projected future trends in fertility and mortality, respectively, by region, and discuss their implications for the coming trends in population ageing.
## B. FERTILITY TRENDS

Of the three demographic processes, historically fertility has been the most influential in shaping trends in the numbers and proportion of older persons in the population over the long term. Total fertility rates have fallen in each of the world's regions. That decline, which is described in the demographic transition, began first in Europe, Northern America and the developed countries of Oceania as far back as the late nineteenth-century. Since the mid-twentieth century, fertility decline has followed in Asia, Latin America and the Caribbean, and Africa.

Figure III.4 illustrates trends in total fertility for the world and six regions, estimated for 1950 to 2015 and projected to 2050 from the 2015 Revision of World Population Prospects. At the global level, total fertility in 1950 was just above 5 children per woman and it has fallen to around 2.5 children per woman in 2015. That global decline reflects reductions in fertility in all six regions. The steepest declines in fertility since 1950 occurred in Asia and Latin America and the Caribbean, where total fertility fell from around 6 children per woman in the mid-twentieth century to around 2.1 children per woman in 2015, which is the level of fertility required to sustain population size over the long term and is referred to as the replacement rate.

<figure><img src="image_32.png" /><figcaption>Figure III.4. Total fertility rate for the world and regions, 1950-2050</figcaption></figure>

Data source: United Nations (2015). World Population Prospects: The 2015 Revision.

Total fertility rates in Oceania, Northern America and Europe were comparatively lower in 1950, at around 3.7, 3.1, and 2.6 children per woman, respectively. Following a brief increase in fertility in the 1950s and early 1960s, fertility decline resumed in these regions. In 2015, total fertility rates had fallen to close to 2.4 children per woman in Oceania, 1.9 children per woman in Northern America, and 1.6 children per woman in Europe. Total fertility was highest in
Africa in 1950, at 6.6 children per woman on average, and while women in Africa had two fewer children on average in 2015 than they did in 1950, the region's total fertility rate of 4.6 children per woman remained the highest in the world.

Projections of future fertility indicate that rates in Africa will continue to fall towards 3.0 children per woman in 2050. Fertility rates in Oceania, Asia and Latin America are also projected to decline, although only slightly, from their 2015 levels, while those in Northern America and Europe are projected to increase, again only slightly from their 2015 levels.

The regional trends in total fertility illustrated in figure III.4 are closely linked to the observed and projected regional trends in the growth of the population of older persons. Figure III.5 charts the estimated and projected regional trends in the average annual rate of change of the population aged 60 years or over from 1980 to 2050 for each of the six regions.

<figure><img src="image_33.png" /><figcaption>**Figure III.5.** Average annual rate of change of the population aged 60 years or over, by region, 1980-2050</figcaption></figure>

*Data source: United Nations (2015). World Population Prospects: The 2015 Revision.*

The influence of the post-World War II baby boom is evident in the spike in the growth rates of the populations of older persons in the early twenty-first century in Europe, Northern America and Oceania. From 2015, the growth of the population aged 60 years or over is projected to slow in Europe, Latin America and the Caribbean, Northern America and Oceania, reflecting the reductions in fertility that led to slowing in the growth of birth cohorts through the latter half of the twentieth century. In Asia, the growth rate of the population of older persons is projected to
decline precipitously after 2025, reflecting the rapid decline in fertility that began in the mid-1960s in that region. In Africa, the pace of growth of the population aged 60 years or over is projected to increase from just over 3 per cent per year in 2010-2015 reaching nearly 3.9 per cent per year in 2040-2045, reflecting the higher fertility rates in the region. The pace of growth of the older population of Africa projected for the 2040s is faster than any region has experienced since 1950 when the data series begins.

### C. TRENDS IN LIFE EXPECTANCIES AND PROBABILITIES OF SURVIVAL TO OLD AGE

As fertility rates fall over time, the size of birth cohorts stabilizes and improvements in longevity become increasingly important drivers of population ageing. Fertility in Europe has been well below the replacement level for more than three decades, thus variations across countries in the rate of growth of the older population are increasingly influenced by disparities in the likelihood of survival to old age. A similar situation is emerging in Northern America and is anticipated to occur in Asia and Latin America and the Caribbean where fertility decline began more recently. This section examines past, present and future mortality risks as summarized in terms of the life expectancies at birth and at age 60, as well as the cohort probabilities of survival to older ages.

**All regions have experienced substantial increases in life expectancy since 1950.**

The life expectancy at birth describes the number of years a person would be expected to live if he or she were exposed throughout life to the prevailing age-specific mortality risks of a given period. Figure III.6 shows the life expectancy at birth for the world and six regions estimated for 1950 to 2015 and projected to 2050 from the *2015 Revision of World Population Prospects*. In 2010-2015, life expectancy at birth globally was 70.5 years, having risen from 46.8 years in 1950-1955. Across the six regions in 2010-2015, the expectation of life at birth was longest in Northern America, at 79.2 years, and shortest in Africa, at 59.5 years. All regions have experienced an increase in life expectancy since 1950, with the fastest increases occurring in Asia, where life expectancy at birth increased from 42.1 years in 1950-1955 to 71.6 years in 2010-2015, and in Latin America and the Caribbean, where it rose from 51.2 years to 74.5 years over the same period.

Improvements in the life expectancy at birth can be driven by mortality decline at various ages. Decomposing the change in life expectancy at birth according to the contribution of mortality reductions among different age groups offers insight into how the drivers of improvements in life expectancy vary across populations at different levels of mortality. The results of this decomposition exercise are shown in figure III.7, which illustrates the contribution of mortality decline below age 5 years, between ages 5 and 59 years, and at age 60 years or over, respectively, to the overall increases in life expectancy at birth between 1995-2000 and 2010-2015 for the world and six regions. At the global level, improved survival between birth and age 5 accounted for close to half of the 4.9-year increase in the life expectancy at birth between 1995-2000 and 2010-2015. Mortality reductions between ages 5 and 59 years and at age 60 years or over each accounted for 25 per cent of the global gain in the life expectancy at birth over that period.
<figure><img src="image_34.png" /><figcaption>**Figure III.6.**
Life expectancy at birth for the world and regions, 1950-2050</figcaption></figure>

Data source: United Nations (2015). *World Population Prospects: The 2015 Revision.*

<figure><img src="image_35.png" /><figcaption>**Figure III.7.**
Contribution of mortality decline at different ages to improvements in the life expectancy at birth between 1995-2000 and 2010-2015, for the world and regions*</figcaption></figure>

*Calculated using life tables from United Nations (2015). *World Population Prospects: The 2015 Revision*. The method applied to decompose the change in life expectancy at birth according to the contribution of improvements in survival at different age groups is that developed by Arriaga (1984) and described in Preston, Heuveline and Guillot (2001), p. 65.
Improvements in survival at age 60 or over accounted for more than half of the total improvement in longevity in Oceania, Europe and Northern America, while reduced mortality at younger ages was more important in Africa, Asia and Latin America and the Caribbean.

Africa, the region with the largest gain in life expectancy at birth since 1995-2000 (7.3 years), attributed a majority of that increase (54 per cent) to improved survival among children under five. Reductions in mortality at age 60 years or over contributed 0.6 years (9 per cent) to the overall increase in life expectancy at birth in Africa. Across the six regions, the largest fraction of the total increase in life expectancy at birth due to reduced mortality at older ages occurred in Northern America, where 71 per cent of the 2.6-year improvement in longevity was due to reduced mortality above age 60. Mortality reductions at older ages accounted for more than half of the total increase in the life expectancy at birth in Europe and Oceania as well. In Latin America and the Caribbean, life expectancy increased by just over four years between 1995-2000 and 2010-2015 and 39 per cent of that gain was due to reductions in mortality risks at age 60 years or over. Asia added five years to the life expectancy at birth between 1995-2000 and 2010-2015 and while most of that gain was due to mortality reductions among children under five years, 23 per cent was attributable to reduced mortality at age 60 years or over.

As the life expectancy at birth increases, improvements in survival at older ages account for a growing proportion of the overall improvement in longevity.

Figure III.8 shows the percentage contribution of increases in the life expectancy at age 60 (both sexes combined) to overall improvements in longevity between 1995-2000 and 2010-2015 versus the life expectancy at birth in 2010-2015 among the 195 countries or areas with at least 90,000 inhabitants in 2015 and for which life expectancy at birth increased over the period. Among those countries with low life expectancy at birth, below 65 years, most of which are located in sub-Saharan Africa, changes in survival probabilities above age 60 accounted for only a small fraction of the change in life expectancy since 1995, at well under 20 per cent in most cases. Examples include Nigeria, where 3.7 per cent of the total 6.0-year increase in life expectancy at birth between 1995-2000 and 2010-2015 was attributable to improved survival at age 60 or over, and Papua New Guinea, where improved survival at older ages accounted for 14.5 per cent of the overall 4.3-year increase in the life expectancy at birth. At the other end of the spectrum, in countries with life expectancy at birth above 75 years, a majority of the improvement in overall longevity was due to improvements in survival above age 60. Reduced mortality at older ages accounted for more than 70 per cent of the net improvement in several countries, including Canada, Ireland, Japan, Singapore, Sweden, the United Kingdom and the United States.

Defined similarly to the life expectancy at birth, the life expectancy at age 60 reflects the number of additional years a 60-year-old person would be expected to live if exposed throughout the remainder of life to the prevailing age-specific mortality rates of a given period. In 2010-2015, 60-year-old persons globally could expect to live an additional 20.2 years on average. Across the six regions, the life expectancy at age 60 was highest in Northern America and Oceania, at 23.5 years and 23.7 years, respectively, and lowest in Africa, at 16.7 years.
<figure><img src="image_36.png" /><figcaption>**Figure III.8.** Contribution of increased longevity after age 60 to total improvement in the life expectancy at birth, 1995-2000 to 2010-2015*</figcaption></figure>

Table III.2 lists the life expectancies at birth and at age 60 for both sexes combined and for each sex separately for the world and six regions. Women tend to live longer than men, on average, a phenomenon linked to both biological and behavioural health advantages of women. At the global level in 2010-2015, women's life expectancy at birth exceeded that of men by 4.5 years. The female advantage in survival from birth was largest in Europe (7.1 years) and Latin America and the Caribbean (6.7 years), and lowest in Africa (2.7 years) and Asia (3.8 years). The female survival advantage persists at older ages. Globally in 2010-2015, 60-year-old women could expect to outlive 60-year-old men by an average 2.8 years and, as with life expectancy at birth, the female survival advantage at age 60 was greatest in Europe (4.0 years) and smallest in Africa (1.5 years).

As with life expectancy at birth, all regions have experienced improvements in the life expectancy at age 60, and are projected to continue to see improvements in survival at older ages over the coming decades.

<footnote>* Calculated using life tables from United Nations (2015). *World Population Prospects: The 2015 Revision*. The method applied to decompose the change in life expectancy at birth according to the contribution of improvements in survival at different age groups is that developed by Arriaga (1984) and described in Preston, Heuveline and Guillot (2001), p. 65. 195 countries or areas with at least 90,000 inhabitants in 2015 and an improvement in the life expectancy at birth between 1995-2000 and 2010-2015.</footnote>
<table><caption>TABLE III.2. LIFE EXPECTANCY AT BIRTH AND AT AGE 60, BY SEX, FOR THE WORLD AND REGIONS, 2010-2015</caption><thead><tr><th rowspan="2"></th><th colspan="3">Life expectancy at birth (years)</th><th colspan="3">Life expectancy at age 60 (years)</th></tr><tr><th>Both</th><th>Female</th><th>Male</th><th>Sex difference (female-male)</th><th>Both</th><th>Female</th><th>Male</th><th>Sex difference (female-male)</th></tr></thead><tbody><tr><td>World</td><td>70.5</td><td>72.7</td><td>68.3</td><td>4.5</td><td>20.2</td><td>21.5</td><td>18.7</td><td>2.8</td></tr><tr><td>Africa</td><td>59.5</td><td>60.9</td><td>58.2</td><td>2.7</td><td>16.7</td><td>17.4</td><td>15.9</td><td>1.5</td></tr><tr><td>Asia</td><td>71.6</td><td>73.6</td><td>69.7</td><td>3.8</td><td>19.4</td><td>20.6</td><td>18.1</td><td>2.5</td></tr><tr><td>Latin America and the Caribbean</td><td>74.5</td><td>77.9</td><td>71.2</td><td>6.7</td><td>21.8</td><td>23.3</td><td>20.1</td><td>3.3</td></tr><tr><td>Europe</td><td>77.0</td><td>80.6</td><td>73.4</td><td>7.1</td><td>21.9</td><td>23.8</td><td>19.8</td><td>4.0</td></tr><tr><td>Oceania</td><td>77.5</td><td>79.7</td><td>75.3</td><td>4.4</td><td>23.7</td><td>25.2</td><td>22.1</td><td>3.1</td></tr><tr><td>Northern America</td><td>79.2</td><td>81.5</td><td>76.8</td><td>4.7</td><td>23.5</td><td>24.9</td><td>21.9</td><td>3.0</td></tr></tbody></table>

Data source: United Nations (2015). World Population Prospects: The 2015 Revision.

Figure III.9 shows the life expectancy at age 60 by sex and for both sexes combined for each of the six regions estimated for the period 1950 to 2015 and projected to 2050. In Africa, the life expectancy at age 60 for both sexes combined rose from 12.5 years in 1950-1955 to 16.7 years in 2010-2015 and is projected to rise further to 19.3 years in 2045-2050. Women in Africa have seen greater advances in survival at older ages on average than men: the female advantage in life expectancy at age 60 widened from 1.0 years in 1950-1955 to 1.5 years in 2010-2015 and is anticipated to widen further to 2.1 years in 2045-2050.

At the mid-twentieth century, life expectancy at age 60 in Asia was similar to that in Africa, at 12.1 years for both sexes combined. Yet advances in survival at older ages have outpaced those in Africa such that by 2010-2015, the expectation of life at age 60 in Asia had grown to 19.4 years. Improvements in survival at older ages have progressed at a similar pace in Latin America and the Caribbean, where the life expectancy at age 60 for both sexes combined increased from 15.1 years in 1950-1955 to 21.8 years in 2010-2015. Both in Asia and in Latin America and the Caribbean, the sex difference in the life expectancy at age 60 widened over time. From a gender gap of less than two years in the 1970s, the female advantage in life expectancy at age 60 in 2010-2015 has grown to 2.5 years in Asia and to 3.3 years in Latin America and the Caribbean.

In Europe, Northern America and Oceania, life expectancy at age 60 ranged from 16 to 17 years in 1950-1955. By 2010-2015, Oceania had added 7.5 years to the life expectancy at age 60; Europe added 5.7; and Northern America added 4.2 years. After widening between 1950 and 1980, the sex differences in life expectancy at older ages in both Northern America and Oceania began to decline, tobacco use, which increased later among women than among men, began to influence similarly their mortality risks (Preston, Glei and Wilmoth, 2010). In Northern America in particular, the female advantage in survival after age 60 narrowed from close to five years in 1975-1980 to three years in 2010-2015. In Europe, the female advantage in survival after age 60 has remained above four years since 1975-1980, due largely to persistent excess mortality risks associated with non-communicable diseases and injuries among males in Eastern Europe (Leon, 2011). A recent study from the World Health Organization attributed the increases in life expectancies at older ages in high-income countries to reductions in tobacco-related mortality
among men and reductions in cardiovascular-disease mortality among both men and women (Mathers and others, 2015).

<figure><img src="image_37.png" /><figcaption>**Figure III.9.** Life expectancy at age 60, by sex and region, 1950-2050</figcaption></figure>

*Data source: United Nations (2015). World Population Prospects: The 2015 Revision.*

Projections indicate that the life expectancy at age 60 will continue to increase in all regions (figure III.9; table III.3). By 2045-2050 the number of additional years a 60-year-old person can expect to live, on average, is expected to increase by 2.9 years at the global level for women and by 3.2 years for men. Men in Latin America and the Caribbean are projected to experience the largest increase in the life expectancy at age 60 by 2045-2050, with an additional 4.0 years,
followed by women in the same region and men in Northern America, each with projected increases in the life expectancy at age 60 of 3.7 years. While improvements in survival at older ages are projected to be slower in Africa than in the other regions, still the life expectancy at age 60 is projected to increase by 2.9 years among women and 2.3 years among men between 2010-2015 and 2045-2050.

<table><caption>TABLE III.3. LIFE EXPECTANCY AT AGE 60, BY SEX, FOR THE WORLD AND REGIONS, 1950-1955, 2010-2015 AND 2045-2050.</caption><thead><tr><th rowspan="3"></th><th colspan="6">Females</th><th colspan="6">Males</th></tr><tr><th colspan="3">Life expectancy at age 60 (years)</th><th colspan="3">Life expectancy at age 60 (years)</th><th colspan="3">Life expectancy at age 60 (years)</th><th colspan="3">Life expectancy at age 60 (years)</th></tr><tr><th>1950-1955</th><th>2010-2015</th><th>2045-2050</th><th>Change between 1950-1955 and 2010-2015 (years)</th><th>Change between 2010-2015 and 2045-2050 (years)</th><th>1950-1955</th><th>2010-2015</th><th>2045-2050</th><th>Change between 1950-1955 and 2010-2015 (years)</th><th>Change between 2010-2015 and 2045-2050 (years)</th><th>Change between 2010-2015 and 2045-2050 (years)</th></tr></thead><tbody><tr><td>World</td><td>15.0</td><td>21.5</td><td>24.4</td><td>6.5</td><td>2.9</td><td>13.0</td><td>18.7</td><td>21.9</td><td>5.7</td><td>3.2</td><td>5.7</td></tr><tr><td>Africa</td><td>13.0</td><td>17.4</td><td>20.3</td><td>4.4</td><td>2.9</td><td>12.0</td><td>15.9</td><td>18.2</td><td>4.0</td><td>2.3</td><td>4.0</td></tr><tr><td>Asia</td><td>12.9</td><td>20.6</td><td>23.9</td><td>7.7</td><td>3.3</td><td>11.3</td><td>18.1</td><td>21.6</td><td>6.8</td><td>3.4</td><td>6.8</td></tr><tr><td>Latin America and the Caribbean</td><td>15.8</td><td>23.3</td><td>27.0</td><td>7.5</td><td>3.7</td><td>14.4</td><td>20.1</td><td>24.0</td><td>5.7</td><td>4.0</td><td>5.7</td></tr><tr><td>Oceania</td><td>18.0</td><td>25.2</td><td>28.1</td><td>7.3</td><td>2.8</td><td>14.8</td><td>22.1</td><td>25.0</td><td>7.3</td><td>2.9</td><td>7.3</td></tr><tr><td>Europe</td><td>17.8</td><td>23.8</td><td>27.2</td><td>6.0</td><td>3.4</td><td>15.5</td><td>19.8</td><td>23.3</td><td>4.3</td><td>3.6</td><td>4.3</td></tr><tr><td>Northern America</td><td>19.0</td><td>24.9</td><td>27.9</td><td>5.9</td><td>3.0</td><td>15.9</td><td>21.9</td><td>25.6</td><td>6.0</td><td>3.7</td><td>6.0</td></tr></tbody></table>

Data source: United Nations (2015). *World Population Prospects: The 2015 Revision*.

While the life expectancies at birth and at age 60 give a useful summary of the mortality risks experienced in a population at a single point in time, the probabilities of survival experienced by different birth cohorts are also instructive on how the mortality risks that people experience over their lifetimes differ according to the year and location of birth. Figure III.10 shows the probabilities of survival to ages 60 and 80 estimated for the 1950-1955 birth cohort, whose survivors were between 60 and 65 years old in 2015, as well as those projected for the 2000-2005 birth cohort, whose survivors were just 10 to 15 years old in 2015 and will celebrate their 60th birthdays in 2060-2065

A majority of the 1950-1955 birth cohort survived to age 60 in all regions except Africa, where just 45 per cent of women and 40 per cent of men lived to their 60th birthdays. Of those born in 1950-1955, women born in Northern America were the most likely to survive to age 60 (89 per cent), followed by women in Europe (82 per cent), women in Oceania and men in Northern America (81 per cent), men in Oceania (76 per cent), women in Latin America and the Caribbean (70 per cent), men in Europe (69 per cent), men in Latin America and the Caribbean and women in Asia (61 per cent), and men in Asia (58 per cent).

Among the 2000-2005 birth cohort, however, projections indicate that more than 8 in 10 men and women will survive to age 60 in every region but Africa, and the probability of survival to age 60 will exceed 90 per cent among women in Europe, Latin America and the Caribbean, Northern America and Oceania, as well as among men in Northern America. Substantial
increases in survival to age 60 are projected for Africa: of those born in the region in 2000-2005, 71 per cent of females and 66 per cent of males are projected to survive to age 60.

<figure><img src="image_38.png" /><figcaption>**Figure III.10.** Probabilities of survival to ages 60 and 80 years among the 1950-1955 and 2000-2005 birth cohorts, by sex and region</figcaption></figure>

*Data source:* Calculated using cohort life tables constructed from United Nations (2015). *World Population Prospects: The 2015 Revision.*
Not only are substantially more people projected to reach old age in the future, but more older people than ever before are projected to survive to age 80 years or over. Among those born in 1950-1955, majorities of women in Europe, Northern America and Oceania are projected to survive to age 80, as are slight majorities of men in Northern America and Oceania. In most of the world, however, survival to age 80 is expected to be comparatively rare among those born at the mid-century. In Latin America and the Caribbean, 47 per cent of women and 34 per cent of men born in 1950-1955 are projected to survive to age 80; in Asia, it's 35 per cent of women and 27 per cent of men; and in Africa it's 19 per cent of women and 14 per cent of men.

Projected survival to age 80 among the 2000-2005 birth cohort show marked improvements in all regions compared to the cohorts born 50 years earlier. Among the 2000-2005 birth cohort, survival to age 80 is expected to be the norm everywhere but in Africa. Around 8 in 10 women born in Northern America and Europe in 2000-2005 are projected to survive to age 80. Probabilities of survival to age 80 among the 2000-2005 birth cohort also exceed 70 per cent among women in Latin America and the Caribbean and Oceania and men in Northern America. While those born in Africa are least likely to survive to advanced older ages, still 43 per cent of women and 33 per cent of men born in Africa during 2000-2005 are projected to live to their 80th birthdays.

The accuracy of projections of life expectancy at older ages will depend on the degree of progress achieved in preventing or postponing mortality caused by many of the diseases associated with old age, in particular non-communicable diseases (NCDs) such as cardiovascular diseases, cancers, diabetes and respiratory diseases. Table III.4 lists the ten leading causes of death to those aged 60 years or over globally, by sex, for the year 2012.

<table><caption>TABLE III.4. TEN LEADING CAUSES OF DEATH OF THOSE AGED 60 YEARS OR OVER GLOBALLY, BY SEX, 2012</caption><thead><tr><th rowspan="2"></th><th colspan="3">Males</th><th colspan="3">Females</th></tr><tr><th>Cause of death</th><th>Deaths (thousands)</th><th>Pct</th><th>Cause of death</th><th>Deaths (thousands)</th><th>Pct</th></tr></thead><tbody><tr><td>1</td><td>Ischaemic heart disease</td><td>2 985 226</td><td>17.8</td><td>Stroke</td><td>3 102 405</td><td>18.6</td></tr><tr><td>2</td><td>Stroke</td><td>2 614 535</td><td>15.6</td><td>Ischaemic heart disease</td><td>3 087 753</td><td>18.5</td></tr><tr><td>3</td><td>COPD<sup>i</sup></td><td>1 541 208</td><td>9.2</td><td>COPD<sup>i</sup></td><td>1 225 348</td><td>7.4</td></tr><tr><td>4</td><td>Lung cancer<sup>ii</sup></td><td>858 088</td><td>5.1</td><td>Lower respiratory infections</td><td>780 539</td><td>4.7</td></tr><tr><td>5</td><td>Lower respiratory infections</td><td>746 789</td><td>4.5</td><td>Diabetes mellitus</td><td>656 592</td><td>3.9</td></tr><tr><td>6</td><td>Diabetes mellitus</td><td>500 976</td><td>3.0</td><td>Hypertensive heart disease</td><td>571 320</td><td>3.4</td></tr><tr><td>7</td><td>Hypertensive heart disease</td><td>399 580</td><td>2.4</td><td>Alzheimer's disease<sup>iii</sup></td><td>455 616</td><td>2.7</td></tr><tr><td>8</td><td>Stomach cancer</td><td>353 508</td><td>2.1</td><td>Lung cancer<sup>ii</sup></td><td>389 966</td><td>2.3</td></tr><tr><td>9</td><td>Prostate cancer</td><td>309 168</td><td>1.8</td><td>Breast cancer</td><td>286 593</td><td>1.7</td></tr><tr><td>10</td><td>Liver cancer</td><td>306 859</td><td>1.8</td><td>Kidney diseases</td><td>279 398</td><td>1.7</td></tr></tbody></table>

Data source: World Health Organization (2014). Global Health Estimates 2014 Summary Tables: Deaths by Cause, Age and Sex. 2000-2012. http://www.who.int/healthinfo/global_burden_disease/en/

<footnote>i Chronic Obstructive Pulmonary Disease</footnote>

<footnote>ii includes trachea and bronchus cancers</footnote>

<footnote>iii and other dementias</footnote>
Cardiovascular diseases, which include heart diseases and stroke, accounted for the largest proportion of deaths among older persons worldwide in 2012. Ischaemic heart disease was the leading cause of death among older men, causing close to 18 per cent of deaths, followed by stroke, which was responsible for another 16 per cent of deaths to men aged 60 years or over. Among older women globally, there were slightly more stroke deaths than deaths due to ischaemic heart disease in 2012; each cause contributed over 18 per cent of deaths to women aged 60 years or over. Hypertensive heart disease accounted for an additional 2.4 per cent of deaths to older men and 3.4 per cent of deaths to older women.

Apart from cardiovascular diseases, chronic obstructive pulmonary disease (COPD), lower respiratory infections, diabetes mellitus and lung cancer (including trachea and bronchus cancers) rank among the ten leading causes of death to both men and women aged 60 years or over globally. Cancers of the stomach, prostate and liver are among the ten leading causes of death to older men, while Alzheimer's disease, breast cancer and kidney diseases rank among the ten leading causes of death to older women.

## D. FERTILITY AND MORTALITY AS DETERMINANTS OF TRENDS IN THE PERCENTAGE OF OLDER PERSONS

The contribution of the demographic transition to the increasing share of older persons in a population can be understood through “population pyramids” that illustrate changes in the size and age structure of a population over time. Figure III.11 contains the population pyramids for three countries—Germany, Brazil and the United Republic of Tanzania—corresponding to three points in time in order to illustrate the implications of the fertility and mortality shifts that characterize the demographic transition for changes in the age distribution of the population.

**Population ageing is an inevitable consequence of the demographic transition.**

The demographic transition began first in Europe and Northern America, where fertility reductions took place over the past two centuries, contributing to their relatively aged population age structures today. In Germany, the total fertility rate in 1950 was 2.1 children per woman, and the proportion of the population aged 60 years or over was just under 15 per cent. Fertility continued to fall in Germany to 1.4 children per woman in 2015, while the proportion of older persons nearly doubled to 28 per cent. While fertility rates in Germany are expected to increase somewhat in the coming decades, they are likely to remain below the replacement level of 2.1 children per woman, and, by 2050, the percentage aged 60 years or over is projected to reach 39 per cent.

The demographic transition began later in most of Asia and Latin America and the Caribbean and thus their populations are youthful compared to Europe and Northern America. In Brazil, fertility in 1950 was 6.2 children per woman, on average, and just 5 per cent of the population was aged 60 years or over. But starting around 1960 fertility declined rapidly in Brazil to 1.8 children per woman in 2015, and it is projected to remain below replacement at least through 2050. Fertility decline has occurred much faster in Asia and Latin America and the Caribbean than in the more developed regions and thus the populations of Asia and Latin America and the
Caribbean are ageing more rapidly. The share of Brazil's population aged 60 years or over, for example, is projected to increase from 12 per cent in 2015 to 29 per cent in 2050.

Many countries in Africa remain in the early stages of the demographic transition: some have begun to see reductions in fertility only recently, while others have yet to see a significant decline in fertility. As a result, while the numbers of older persons have grown, their share of the overall population has remained fairly small. In the United Republic of Tanzania, for example, total fertility in 2015, at 5.1 children per woman, was still comparatively high, although it had fallen from 6.7 children per woman in 1950. Consequently, there has been little change in the proportion of older persons in Tanzania: it increased only slightly, from 4 per cent in 1950 to 5 per cent in 2015. Fertility in Tanzania is projected to continue a relatively slow decline towards 3.3 children per woman in 2050 and the percentage of the population aged 60 years or over is projected to rise gradually to reach 7 per cent by the mid-century.

The size of the population of older persons over the near term is fairly certain, since: 1) the people who will be aged 60 years or over in 2030 are today's population aged 45 years or over; and 2) adult mortality risks tend to change slowly over time. The size of the population of children, however, is less certain, since total fertility rates can shift relatively quickly. This uncertainty in the future numbers of children shapes the uncertainty associated with projections of the proportion of older persons over the medium- to long-term.

Figure III.12 displays the proportion of the population aged 60 years or over projected in the medium variant, as well as two alternative hypothetical fertility scenarios for three countries with disparate levels of fertility in 2015. The high-fertility scenario illustrates what the proportion of older persons would be if the total fertility rate were 0.5 children per woman higher than in the medium variant projection, while the low-fertility scenario illustrates that proportion if the fertility rate were 0.5 children per woman lower than in the medium variant projection.

In Japan where total fertility averaged 1.5 children per woman in 2015, the population has aged rapidly over the past 65 years, from 8 per cent aged 60 years or over in 1950 to 33 per cent in 2015. According to the medium variant projection, fertility in Japan will remain well below the replacement level of 2.1 children per woman and Japan's population will continue to age, reaching 37 per cent aged 60 years or over in 2030 and 42 per cent in 2050. However, if future fertility differs from the medium variant, the population ageing process in Japan could be accelerated or slowed. If future total fertility is 0.5 children per woman lower than in the medium variant projection, the proportion aged 60 years or over in 2050 will be 4 percentage points higher, at close to 47 per cent, while if it is 0.5 children per woman higher than in the medium variant projection, the proportion of older persons in 2050 will be more than 3 percentage points lower, at 39 per cent. However, since both the high- and low-fertility scenarios fall well outside the 95 per cent prediction interval associated with probabilistic projections of total fertility in Japan (data not shown), deviation of this magnitude from the medium variant projection of the proportion of older persons is highly unlikely.
<figure><img src="image_39.png" /><figcaption>Figure III.11.
Population age structure in Germany, Brazil and the United Republic of Tanzania, 1950, 2015 and 2050</figcaption></figure>

Data source: United Nations (2015). *World Population Prospects: The 2015 Revision*.
<figure><img src="image_40.png" /><figcaption>Figure III.12. Percentage aged 60 years or over under three fertility projection scenarios, and total fertility rate (TFR), Japan, Pakistan and Nigeria, 1950-2050*</figcaption></figure>

*Data source: United Nations (2015). World Population Prospects: The 2015 Revision.*

* "Medium" refers to the medium variant projection. "Low" refers to a projected fertility scenario in which total fertility is 0.5 children per woman lower than the medium variant projection, while "High" refers to a projected fertility scenario in which total fertility is 0.5 children per woman higher than the medium variant projection.
In countries where total fertility has been higher than in Japan and the pace of population ageing has been slower, variations in projected fertility of 0.5 children per woman in either direction yield smaller changes to the projected proportion of older persons for 2050. In Pakistan for example, total fertility remained above six children per woman until 1990 when birth rates began to fall precipitously, reaching 3.4 children per woman in 2015. Reflecting persistently high historical fertility levels, the proportion aged 60 years or over in Pakistan declined somewhat between 1950 and 1970, from close to 8 per cent to just under 6 per cent, and has risen only slightly since then to 6.6 per cent in 2015. Recent fertility declines are projected to yield accelerated population ageing in Pakistan in the coming decades, however, with the proportion of older persons expected to increase to 8 per cent in 2030 and to close to 13 per cent in 2050. Projection scenarios with a trajectory of the total fertility rate 0.5 children per woman lower or higher than the medium variant produce projected proportions aged 60 years or over in 2050 for Pakistan that range from 11.6 per cent in the high-fertility scenario to 14.5 per cent in the low fertility scenario. Unlike for Japan, the high- and low-fertility scenarios for Pakistan fall within the 95 per cent prediction interval of the probabilistic projections of total fertility, but at the margins of the 80 per cent prediction interval.

Fertility decline in Nigeria began relatively recently and thus the country has not yet experienced an increase in the proportion of older persons. In 2015, 4.5 per cent of Nigeria's population was aged 60 years or over and that proportion is projected to change only slightly (to 4.8 per cent) through 2030. By 2050, however, the proportion of older persons in Nigeria is expected to have begun to grow more significantly, reaching 6.3 per cent in the medium variant projection, 7.0 per cent if total fertility falls to 0.5 children per woman lower than the medium variant, or 5.8 per cent if total fertility declines less rapidly, to a level that is 0.5 children per woman higher than in the medium variant. Higher fertility in Nigeria is also associated with greater uncertainty in projected future fertility. Both the high- and low-fertility scenarios fall well within the 80 per cent prediction interval associated with the probabilistic projections of total fertility for Nigeria.

E. INTERNATIONAL MIGRATION AND POPULATION AGEING

While declining fertility and increasing longevity are the key drivers of population ageing globally, international migration has also contributed to changing population age structures in some countries and regions. In countries that are experiencing large immigration flows, international migration can slow the ageing process, at least temporarily, since migrants tend to be in the young working ages. However, migrants who remain in the country eventually will age into the older population. Thus, over the long term, only sustained large flows of young immigrants could slow or reverse population ageing. A 2001 study from the United Nations concluded that in several European countries, as well as in Japan, the Republic of Korea and the United States, levels of immigration would need to be much higher than had been observed in the past in order for international migration to offset population ageing, and thus, replacement migration alone was unlikely to be an effective policy response to population ageing (United
Nations, 2001). Other studies also have concluded that the levels of international migration required to offset population ageing are implausible (see, for example, Bijak and others, 2007).<fnref n="14" />

Despite these conclusions, there is some evidence that countries are increasingly turning to international migration as a means to expand the size of the labour force in the context of an ageing population. The number of countries with policies to increase rates of immigration has been rising steadily over time from 8 in 1996 to 11 in 2005 and to 22 in 2013. Among those countries enacting policies to raise the level of immigration, most have identified population ageing as a “major concern” (figure III.13). In 2013, population ageing was cited as a major concern by 20 of the 22 countries (91 per cent) with policies to raise immigration levels. By comparison, 47 per cent of countries that had not enacted policies to promote immigration identified population ageing as a “major concern” (United Nations, 2014c).

<figure><img src="image_41.png" /><figcaption>**Figure III.13.** Distribution of countries according to the policy on immigration and level of concern about population ageing, 2005 and 2013</figcaption></figure>

Data source: United Nations (2014c). World Population Policies Database 2013.

Over time, the number of countries seeking to maintain their levels of immigration also has increased (from 104 in 2005 to 120 in 2013), while the number seeking to lower levels of immigration has declined (from 43 in 2005 to 30 in 2013). Half of the countries with policies to maintain levels of immigration in 2013 had identified population ageing as a major concern.

<footnote n="14">¹⁴ This conclusion may soon be challenged by recent experience in Europe, where current evidence suggests that flows of migrants, refugees and asylum seekers from the Middle East and Africa are reaching historically unprecedented magnitudes (OECD, 2015a, http://www.oecd.org/migration/Is-this-refugee-crisis-different.pdf).</footnote>
Conversely, the emigration of young workers has accelerated the population ageing process in some countries, particularly in Eastern Europe where increasing access to European Union labour markets as well as the economic crisis that began in 2008 have contributed to large emigration flows. In Lithuania, for example, net emigration over the 2000s was equivalent to 13 per cent of the population, while in Latvia and Estonia it was 9 per cent and 6 per cent, respectively (OECD, 2013a). Young people aged 20 to 35 accounted for a disproportionate share of emigrants from these countries (OECD, 2013a), thereby contributing to intensify population ageing there. Between 2000 and 2015, the share of older persons in Lithuania grew from 19 per cent to 25 per cent and in both Latvia and Estonia from 21 per cent to 25 per cent.

Looking to the near future, international migration is projected to have only small effects on the pace of population ageing in most countries. The magnitude of the impact of international migration on projected trends in population ageing can be understood through a comparison of the projected proportion of the population aged 60 years or over in 2030 according to the "medium variant" to the projected proportion aged 60 years or over according to a "zero migration" scenario. The medium variant reflects median projected future levels of fertility and mortality rates, as well as future migration levels that take into account levels and trends in migration observed in the country during the recent past. The zero migration scenario considers what the future population would be under the median fertility and mortality levels, but in the absence of any international migration. In 163 out of 201 countries or areas with at least 90,000 inhabitants in 2015, the difference in the percentage aged 60 years or over in 2030 between the medium variant and zero migration scenarios amounts to less than 1 percentage point.

Net migration is projected to slow population ageing in 24 of the 38 countries or areas where projected net migration implies a greater than one point difference in the percentage of the population aged 60 years or over in 2030 (table III.5). In the remaining 14 countries, net migration is expected to actually accelerate population ageing between 2015 and 2030 (table III.6). Labour migration to the Gulf States of Bahrain, Kuwait, Qatar and the United Arab Emirates is projected to counter population ageing trends so that the projected percentage of the population aged 60 years or over in 2030 is substantially lower than it would be if no migration were to take place. In Qatar, for example, the medium variant projection indicates that 7.9 per cent of the population will be aged 60 years or over in 2030, but it would be 11 per cent if no migration were to take place between 2015 and 2030. In the United Arab Emirates, older persons are projected to account for 11.3 per cent of the population in 2030 according to the medium variant, but would account for 14.2 per cent in the absence of migration.

Other populations that receive a large number of migrants in the working ages are also projected to see slower population ageing as a result, including Luxembourg, Macao, Australia, Switzerland, Canada, the Channel Islands, Hong Kong, special administrative region of China, and Norway, where the percentage aged 60 years or over is projected to be more than 2 percentage points lower in 2030 than it would be in the absence of migration. Migration has the largest impact on the pace of population ageing in Luxembourg: if there were no net migration to Luxembourg the projected percentage of persons aged 60 years or over in 2030 would be 28.9 per cent instead of the 24.7 per cent projected in the medium variant.
International migration is anticipated to accelerate population ageing in some countries, due to projected net emigration of working aged people, net immigration of older people, or both. Many of the populations that are projected to see ageing accelerated by migration between 2015 and 2030 are located in the Caribbean. In Barbados, for example, the proportion aged 60 years or over in 2030 is projected to reach 27.7 per cent in the medium variant, compared to 25.4 per cent with no migration. In Guadeloupe, the population is projected to become 30.5 per cent aged 60 years or over in 2030, compared to 29.3 per cent with no migration. Outside of the Caribbean region, Lebanon, Samoa, Albania, Tonga, Sri Lanka and Réunion are also projected to see population ageing accelerated as a result of international migration.

<table><caption>TABLE III.5. COUNTRIES OR AREAS WHERE INTERNATIONAL MIGRATION IS PROJECTED TO SLOW POPULATION AGEING BY AT LEAST 1 PERCENTAGE POINT BY 2030</caption><thead><tr><th rowspan="2"></th><th colspan="3">Percentage of population aged 60 years or over</th><th rowspan="2">Difference<br/>between<br/>medium<br/>variant and<br/>zero<br/>migration</th></tr><tr><th>2015</th><th>2030</th><th>2030</th></tr></thead><tbody><tr><td>Luxembourg</td><td>19.1</td><td>24.7</td><td>28.9</td><td>-4.1</td></tr><tr><td>Qatar</td><td>2.3</td><td>7.9</td><td>11.0</td><td>-3.0</td></tr><tr><td>China, Macao SAR</td><td>14.8</td><td>25.7</td><td>28.6</td><td>-2.9</td></tr><tr><td>United Arab Emirates</td><td>2.3</td><td>11.3</td><td>14.2</td><td>-2.9</td></tr><tr><td>Bahrain</td><td>3.9</td><td>10.8</td><td>13.7</td><td>-2.8</td></tr><tr><td>Kuwait</td><td>3.4</td><td>8.9</td><td>11.5</td><td>-2.7</td></tr><tr><td>Australia</td><td>20.4</td><td>24.6</td><td>27.2</td><td>-2.5</td></tr><tr><td>Switzerland</td><td>23.6</td><td>30.6</td><td>33.1</td><td>-2.4</td></tr><tr><td>Canada</td><td>22.3</td><td>29.4</td><td>31.6</td><td>-2.3</td></tr><tr><td>Channel Islands</td><td>23.6</td><td>31.0</td><td>33.1</td><td>-2.1</td></tr><tr><td>China, Hong Kong SAR</td><td>21.7</td><td>33.6</td><td>35.6</td><td>-2.0</td></tr><tr><td>Norway</td><td>21.8</td><td>26.2</td><td>28.2</td><td>-2.0</td></tr><tr><td>Sweden</td><td>25.5</td><td>28.6</td><td>30.2</td><td>-1.6</td></tr><tr><td>Singapore</td><td>17.9</td><td>30.7</td><td>32.0</td><td>-1.3</td></tr><tr><td>Belgium</td><td>24.1</td><td>29.5</td><td>30.7</td><td>-1.2</td></tr><tr><td>Austria</td><td>24.2</td><td>32.4</td><td>33.5</td><td>-1.1</td></tr><tr><td>Denmark</td><td>24.7</td><td>29.4</td><td>30.5</td><td>-1.1</td></tr><tr><td>United Kingdom</td><td>23.0</td><td>27.8</td><td>29.0</td><td>-1.1</td></tr><tr><td>United States of America</td><td>20.7</td><td>26.1</td><td>27.2</td><td>-1.1</td></tr><tr><td>New Caledonia</td><td>14.5</td><td>19.6</td><td>20.7</td><td>-1.1</td></tr><tr><td>Curaçao</td><td>21.1</td><td>28.4</td><td>29.5</td><td>-1.1</td></tr><tr><td>Germany</td><td>27.6</td><td>36.1</td><td>37.2</td><td>-1.1</td></tr><tr><td>Cyprus</td><td>18.0</td><td>23.7</td><td>24.8</td><td>-1.0</td></tr><tr><td>Italy</td><td>28.6</td><td>36.6</td><td>37.6</td><td>-1.0</td></tr></tbody></table>

Data source: United Nations (2015). *World Population Prospects: The 2015 Revision*.
<table><caption>TABLE III.6. COUNTRIES OR AREAS WHERE INTERNATIONAL MIGRATION IS PROJECTED TO ACCELERATE POPULATION AGEING BY AT LEAST 1 PERCENTAGE POINT BY 2030</caption><thead><tr><th rowspan="2"></th><th colspan="3">Percentage of population aged 60 years or over</th><th rowspan="2">Difference<br/>between<br/>medium<br/>variant and<br/>zero<br/>migration</th></tr><tr><th>2015</th><th>Medium<br/>variant<br/>projection</th><th>Zero<br/>migration<br/>scenario</th></tr></thead><tbody><tr><td>Barbados</td><td>19.8</td><td>27.7</td><td>25.4</td><td>2.3</td></tr><tr><td>Lebanon</td><td>11.5</td><td>19.2</td><td>17.0</td><td>2.2</td></tr><tr><td>Samoa</td><td>7.9</td><td>12.1</td><td>10.3</td><td>1.8</td></tr><tr><td>United States Virgin Islands</td><td>24.1</td><td>32.2</td><td>30.5</td><td>1.7</td></tr><tr><td>Grenada</td><td>10.2</td><td>14.3</td><td>12.8</td><td>1.5</td></tr><tr><td>Jamaica</td><td>12.8</td><td>18.7</td><td>17.3</td><td>1.5</td></tr><tr><td>Guadeloupe</td><td>20.2</td><td>30.5</td><td>29.3</td><td>1.2</td></tr><tr><td>Albania</td><td>17.8</td><td>25.5</td><td>24.3</td><td>1.2</td></tr><tr><td>Tonga</td><td>8.2</td><td>10.5</td><td>9.4</td><td>1.2</td></tr><tr><td>Sri Lanka</td><td>13.9</td><td>21.0</td><td>19.9</td><td>1.2</td></tr><tr><td>Guyana</td><td>8.3</td><td>14.9</td><td>13.8</td><td>1.1</td></tr><tr><td>St. Vincent and the Grenadines</td><td>10.9</td><td>18.3</td><td>17.2</td><td>1.1</td></tr><tr><td>Martinique</td><td>26.2</td><td>38.5</td><td>37.4</td><td>1.1</td></tr><tr><td>Réunion</td><td>15.1</td><td>25.5</td><td>24.4</td><td>1.0</td></tr></tbody></table>

Data source: United Nations (2015). *World Population Prospects: The 2015 Revision*.
<figure><img src="image_42.png" /></figure>
# IV. Population ageing and sustainable development

World population ageing is a consequence, in part, of substantial progress in improving the health and well-being and reducing mortality risks faced by people around the globe. People are living longer, and, in many cases, healthier lives than ever before. The benefits of greater longevity to individuals, families and society are many. Longer lives can afford individuals opportunities to prolong their working life, embark on second careers, or pursue varied interests in old age. Families benefit from the contributions of older generations, for example, through financial support, assistance with household maintenance, or participation in childcare. Societies benefit from the wisdom and experience of older persons and from their contributions to the labour force, as well as from their volunteerism, philanthropy and civic engagement.

At the same time, many countries are concerned about population ageing, especially with respect to its implications for the systems and institutions that aim to protect and preserve people's well-being. In many countries, the number of older persons is growing faster than the number of people in the traditional working ages, giving rise to concerns about the fiscal sustainability of pension systems that rely upon contributions from current workers to pay benefits to retirees. Moreover, population ageing and growth in the number of persons at very advanced ages put pressure on health systems, which must adapt to meet the growing demand for care, services and technologies to prevent and treat non-communicable diseases and chronic conditions associated with old age.

This chapter explores the implications of recent and projected trends in population ageing for efforts towards progress in achieving the 2030 Agenda for Sustainable Development. In particular, the three sections of this chapter address the challenges posed by the growth in the number and share of older persons in the population for efforts to eradicate poverty and promote economic growth, to ensure the sustainability of pension systems and to promote health and well-being at all ages.

## A. AGEING, POVERTY AND ECONOMIC GROWTH

This section draws upon the latest empirical evidence and economic literature in order to: 1) describe the poverty status of older persons relative to the population overall; 2) analyse older persons' levels of consumption compared to other age groups and across countries at different levels of national income; and 3) assess the macroeconomic implications of population ageing on economic growth.

**Poverty rates among older persons relative to the general population vary, largely due to the coverage and adequacy of old-age social protection systems.**

Describing the poverty rates of people in different age groups is challenging for a number of reasons. First, surveys generally measure income and consumption at the household level rather than for individuals at different ages. Household welfare does not necessarily reflect accurately the welfare of all individuals in the household because the household resources could be distributed unequally across its members. Second, different definitions and approaches to
measuring poverty present difficulties for comparisons across studies and populations. The national poverty lines defined by countries often differ from the World Bank's poverty threshold of US$1.90 a day<fnref n="15" /> or from the (relative) measure of half the median national income used by the Organization for Economic Cooperation and Development (OECD). Third, discussions of age patterns of poverty in international comparative perspective are further challenged by the absence of an international harmonized database of poverty rates disaggregated by age. The World Bank's comprehensive poverty database covering all countries (PovcalNet) is not age disaggregated. Thus, evidence on poverty rates among older persons and for other age groups is limited to selected country-level or regional-level studies.

Nevertheless, available data on the prevalence of poverty by age offer some useful insights into how well older persons are faring relative to people in other age groups. The following section reviews the existing evidence on poverty rates among older persons in relation to the poverty rates of the population as a whole, acknowledging the differences in concepts and measures across studies and regions.

**Older persons tend to be poorer than the general population in African countries and are more often less poor than the overall population in Latin America and Europe.**

Figure IV.1 plots, by region, the poverty rate for older persons against the poverty rate for the total population for countries with available data. Estimates for countries in Africa, depicted in the upper-left chart of the figure, are from a 2005 study that assessed poverty among older persons using the national definition of the poverty line between 1998 and 2001 (Kakwani and Subbarao, 2005). For the 18 Latin American countries depicted in the upper-right chart of the figure, poverty estimates are from a 2011 study of the Socioeconomic Database for Latin America and the Caribbean (SEDLAC) (Cotlear and Tornarolli, 2011), and the poverty threshold is defined as US$2.5 per day. Estimates for countries located in Eastern and Southern Europe, plotted in the lower-left chart, are from a World Bank study (Bussolo and others, 2015) that defined the poverty line at US$5 per day. Estimates for selected OECD countries, depicted in the lower-right chart of the figure, are as reported by the OECD (2015b) using the relative poverty line definition of half the median disposable income in the country.

The 45-degree line in each chart represents the points at which the poverty rates among older persons are equivalent to the poverty rates for the population overall. Points that fall above the 45-degree line indicate that poverty rates among older persons exceed those of the total population, while the points that fall below the 45-degree line indicate that poverty rates among older persons are lower than among the total population.

**Older persons in most sub-Saharan African countries are most commonly poorer than other age groups.**

While most African countries are not far from the 45-degree line, indicating that poverty rates among older persons were similar to those of the total population, disparities were evident in some countries. In Zambia, for example, 80 per cent of people aged 60 years or over were

<footnote n="15">¹⁵ In October 2015 the World Bank revised its definition of “extreme poverty” to living on less than $1.90 per day from $1.25 per day, reflecting the latest updates in purchasing power parities. (http://www.worldbank.org/en/publication/global-monitoring-report/poverty-forecasts-2015).</footnote>
under the national poverty line, compared to around 67 per cent of the general population overall. By comparison, in some countries in Africa, including Burundi, Madagascar, Mozambique and Nigeria, older persons were somewhat less poor, on average, than the total population.

<figure><img src="image_43.png" /><figcaption>Figure IV.1.
Poverty rate for older persons versus the poverty rate for the total population, recent estimates for selected countries</figcaption></figure>

Data sources: a) Data for Africa are from Kakwani and Subbarao (2005), refer to a year between 1998 and 2001, and the poverty line is defined according to the national poverty definition. b) Data for Latin America are from Cotlear and Tornarolli (2011), refer to the period between 2005 and 2007, and the poverty line is defined as US$2.5 per day. c) Data for Eastern and Southern Europe are from Bussolo and others (2015), Golden Ageing, Table 5.2, refer to the year 2012 and the poverty line is defined as US$5 per day. d) Data for OECD countries are from OECD (2015b), Table 1.A1.1, refer to the 2013 or the latest available year, and the poverty line is defined as 50 per cent of the median disposable income.
In assessing poverty rates among older persons in Africa, Kakwani and Subbarao (2005) also found some significant rural-urban differences with a much higher proportion of single older persons living in poverty in rural areas compared to urban areas. In addition, poverty rates were higher for older persons in countries with high prevalence of HIV. Excess mortality among young adults in these countries meant that many older persons lost the support that they would have received from their adult children and they also have assumed greater responsibility for generating income and caring for children in their extended families. Deaton and Paxson (1997) found that the poverty rate for older persons was higher than that for younger adults in South Africa in 1996. Some significant differences were found by gender, wherein households headed by older women were more prone to poverty than households headed by older men, especially in parts of sub-Saharan Africa that are patriarchal (Kakwani and Subbarao, 2005). In societies where women lack certain rights to own or inherit property, widows face a significant risk of poverty following the dispossession of their house and land by the deceased husband's kin (Toulmin, 2006).

**In Latin America, poverty rates among older persons tend to be lower than for the population as a whole.**

For the Latin American region as a whole, an estimated 19 per cent of people aged 60 years or over were poor in the mid-2000s, with the poverty line defined as US$2.5 per day. By comparison, 30 per cent of children under age 15, 20 per cent of young adults aged 15-24 years, and 23 per cent of the population overall were poor (Cotlear and Tornarolli, 2011). In several countries, such as Argentina, Brazil, Chile and Uruguay, where pension systems include minimum levels of support for both contributors and non-contributors (for example, persons who are unable to contribute due to poverty or disability), older persons were substantially better off, on average, compared to the population as a whole. In Argentina, just 4 per cent of older persons were poor, compared to 11 per cent of the overall population. The national poverty rate was higher in Brazil, at close to 18 per cent, but there, too, just 4 per cent of older persons were poor.

Pensions are generous in some countries in Latin America compared to other developing countries, and public spending was highly skewed towards older persons. As a result, older persons usually had higher average levels of welfare relative to children. Examples of countries where the poverty rate among children exceeded that of older persons include Brazil, Chile and Uruguay (Bravo and Holz, 2011; Turra and others, 2011). By contrast, social pension benefits were lower in Colombia, Costa Rica and Mexico, where older persons were slightly poorer, on average, than the total population. In addition, the incidence of poverty in these three countries was higher for older persons living in rural areas and for the oldest-old (aged 80 years or over) (Cotlear and Tornarolli, 2011).

As noted earlier, conclusions about the relative poverty of older persons are sensitive to the choice of the poverty definition (Deaton and Paxson, 1997). Indeed, another study of Latin American countries that used the relative poverty measure of 50 per cent of the national median income arrived at a slightly different conclusion. Using the same SEDLAC database as Cotlear and Tornarolli (2011), Dethier and others (2010) concluded that poverty rates were consistently lower for older persons relative to the total population only in Argentina, Brazil, Chile and Uruguay. Using the half the median income definition of poverty, poverty rates among older
persons in Bolivia, Colombia, Costa Rica, Honduras and Mexico were found to be higher than for the population overall.

**In Eastern and Southern Europe, older persons tend to be less poor than average.**

A 2015 World Bank study of selected countries in Eastern and Southern Europe assessed the poverty rates among older persons using a poverty definition of US$5 per day purchasing power parity (Bussolo and others, 2015). Among the 21 countries plotted in the lower-left chart of figure IV.1, only the Republic of Moldova lies above the 45-degree line, indicating that older persons were, on average, somewhat poorer than the total population in that country. For all the 21 countries in Eastern and Southern Europe, the poverty rate among the older population (aged 65 years or over) was 10.7 per cent on average, compared to an average 14.5 per cent for the total population. As many of these countries transitioned away from socialist economies, older people were able to build up some assets while still receiving relatively generous pensions, and thus became wealthier than other age groups (Bloom and others, 2011).

**In most countries in Northern and Western Europe, poverty rates among older persons are lower than for the overall population.**

Estimates from the OECD, shown in the lower-right chart of figure IV.1, summarize poverty rates according to the measure of 50 per cent of median disposable income (OECD, 2015b). The prevalence of poverty was lower for older persons (aged 65 years or over) than for the total population in numerous countries, including Denmark, Iceland, Ireland, Luxembourg, the Netherlands and Portugal, among others. This is explained by the current generation of older persons having benefitted from long and significant contributions to private or public social security systems, as well as their private asset accumulation. However, the incidence of poverty was higher, on average, for older persons relative to the general population in Australia, Austria, Switzerland, the United Kingdom and the United States of America. Some factors contributing to the higher relative poverty rates among older persons in these countries included the high costs of health care, modest public pensions and relatively high earnings among younger working-age adults.

**In Asian countries, poverty rates among older persons are often similar to or slightly higher than those for other age groups.**

Data on poverty rates by age group are more limited in Asia than in other developing regions. Evidence from China and Indonesia suggests that poverty rates are somewhat higher for older persons than for others. In China, home to nearly a quarter of the world's older population, a World Bank report (2009) showed that nearly 13 per cent of Chinese older persons had incomes below the US$1 per day per capita consumption poverty line in 2003, compared to 12 per cent of the working-age population (defined in this study as ages 16-60 years) and 17 per cent of children (younger than 16 years). The welfare of older persons in China varied considerably according to living arrangement, health status and location. Older persons who lived alone, in rural areas, with poor health status, without pensions, or who were illiterate, were more likely to be poor (Park and others, 2012). However, a separate study that assessed poverty by measuring consumption at the individual level rather than at the household level found that Chinese older
persons who lived with grandchildren, without adult children or who lived in multi-generational households with young children fared worse than those who lived alone (Tung and Lai, 2011). Older persons living in these households tended to have lower levels of consumption as some of the family resources, either from the working-age adults or the older persons themselves, were diverted to the young dependents. Population ageing is occurring rapidly in China due to the precipitous decline in fertility that began in the 1970's. In response to population ageing and a growing concern that the future older population in China will have few children on whom to rely for support, the Chinese government has recently lifted its one-child policy (Zhao, 2015).

In Indonesia, older persons were also found to be slightly poorer, on average, than younger people in 2012 (Priebe and Howell, 2014). Measured by the national consumption poverty line, an estimated 13 per cent of older persons in Indonesia were considered to be poor, compared to 12 per cent of people in other age groups. An estimated 2.5 million older persons lived in poverty in Indonesia, where the formal pension system covered only a minority of older persons.

Conversely, evidence for India indicates that the poverty rate of older persons is lower than that of other age groups. In India, home to 13 per cent of the world's older population, households with older persons were not found to be poorer than households without an older person (Pal and Palacios, 2008; Srivastava and Mohanty, 2012). An estimated 18 million older persons (approximately one in five older persons) lived below the national consumption poverty line in 2004 in India (Srivastava and Mohanty, 2012).

**Data on age patterns of consumption document the relative welfare of older persons in the population.**

Although the level of consumption is not equivalent to welfare, consumption is a major determinant of welfare and therefore garners attention from both researchers and policymakers. In particular, the “lifecycle hypothesis” of consumption and saving proposes that individuals tend to smooth their consumption over time in order to maximize their lifetime welfare. To accomplish that, people may borrow against their future earnings when young, save during their working years and consume accumulated assets during retirement. Because data typically are collected at the household level, empirical research on the consumption of individuals at different ages is not straightforward. The National Transfer Accounts (NTA) project has addressed this issue by developing a consistent conceptual and accounting framework, as well as standardized estimation methods that have yielded a harmonized database of production, consumption and inter-age reallocations for 36 countries, representing all regions of the world.<fnref n="16" /> NTA methods allocate household consumption to individuals using a combination of regression methods for age-specific consumption on education and health care expenditures, as well as weights for other types of consumption. Both private and public consumption are taken into account. Details of the methodology can be found in the *National Transfer Accounts Manual* (United Nations, 2013). Selected findings on the levels of consumption among older persons are highlighted below.

<footnote n="16">¹⁶ United Nations (2013) *National Transfer Accounts Manual: Understanding and Measuring the Generational Economy*.</footnote>