Age structure

Number of persons aged 65+ has almost doubled since 1990
Half of the population in developing economies is younger than 30
In 2017, 74 African children per 100 persons of working age
Old-age dependency projected to rise throughout the world
Dependency ratio, 2017(Percentage)
Economies

    Aging of the world population

    In 2017, persons of working age accounted for 65 per cent of the global population. Children made up 26 per cent and older persons 9 per cent. Since the 1990s, the child population has grown only slightly, by around one tenth, whereas the working age population has risen by one half and the number of older persons has doubled. According to projections, by 2050, only 21 per cent of the global population will be under the age of 15, while 16 per cent will be more than 64 years old.

    Dependency ratios throughout the world

    Many Sub-Saharan African economies, in 2017, had on average over 80 persons of non-working age per 100 persons of working age. In most developed economies, this percentage was smaller, as reflected by dependency ratios between 50 and 65 per cent. Lower ratios were characteristic for transition economies and for developing economies in Eastern and South-Eastern Asia.

    Figure 1World population by age group (Billions)

    Evolving population pyramids

    The population pyramid for developing economies has a triangular shape with the highest population shares in age classes below 30 years and diminishing shares in older age cohorts. In other words, in 2017, around half of the population in developing economies was younger than 30 years; in developed economies this was the case for only one third. The pyramid for developed economies is bell shaped, displaying a concentration of people in the age classes around 50 years. With extending life expectancy and aging populations, more top-heavy population pyramids are anticipated in the future.

    Figure 2Population pyramids, 2017

    Differences in the structure of dependency

    The average dependency ratio for developing and developed economies was almost the same in 2017, standing at 53 and 55 per cent, respectively. However, developing economies show relatively high child dependency, in accordance with their triangular population pyramid. Child dependency is particularly high in Africa, where it reached 74 per cent in 2017. In developed economies, by contrast, dependency is primarily the result of a large proportion of older persons.

    By 2050, child dependency is projected to decrease considerably in developing economies. Old-age dependency is projected to rise throughout the world. By 2050, developed economies are expected to show a higher dependency ratio than Africa.

    Figure 3Dependency ratio by age structure (Percentage)

    Note: The total dependency ratio is the sum of the child and old-age dependency ratios.

    Summary tables

    Table 1

    Age structure by group of economies

    Group of economies

    Year

    Population

    Dependency ratio

    (Millions)

    (Percentage)

    0-14

    15-64

    65+

    Child
    (0-14)

    Old-age
    (65+)

    Total

    World

    2012

    1 889

    4 678

    560

    40.4

    12.0

    52.4

    2017

    1 957

    4 936

    657

    39.6

    13.3

    52.9

    2050

    2 083

    6 142

    1 546

    33.9

    25.2

    59.1

    Developing economies

    2012

    1 659

    3 781

    348

    43.9

    9.2

    53.1

    2017

    1 721

    4 046

    419

    42.5

    10.4

    52.9

    2050

    1 854

    5 306

    1 182

    34.9

    22.3

    57.2

    Developing economies: Africa

    2012

    456

    610

    38

    74.8

    6.2

    81.0

    2017

    512

    699

    44

    73.3

    6.3

    79.7

    2050

    811

    1 564

    150

    51.9

    9.6

    61.5

    Developing economies: America

    2012

    163

    401

    43

    40.5

    10.6

    51.1

    2017

    160

    429

    51

    37.2

    11.9

    49.1

    2050

    132

    493

    150

    26.8

    30.4

    57.2

    Developing economies: Asia and Oceania

    2012

    1 040

    2 770

    267

    37.5

    9.7

    47.2

    2017

    1 049

    2 918

    324

    36.0

    11.1

    47.0

    2050

    910

    3 249

    881

    28.0

    27.1

    55.1

    Transition economies

    2012

    56

    211

    35

    26.6

    16.5

    43.1

    2017

    62

    208

    37

    29.7

    18.0

    47.7

    2050

    56

    192

    60

    29.3

    31.5

    60.8

    Developed economies

    2012

    174

    685

    177

    25.4

    25.9

    51.3

    2017

    173

    682

    200

    25.5

    29.4

    54.8

    2050

    173

    645

    304

    26.8

    47.1

    73.9

    Selected groups

    Developing economies excluding China

    2012

    1 416

    2 770

    227

    51.1

    8.2

    59.3

    2017

    1 472

    3 036

    269

    48.5

    8.9

    57.4

    2050

    1 663

    4 491

    823

    37.0

    18.3

    55.3

    Developing economies excluding LDCs

    2012

    1 294

    3 286

    317

    39.4

    9.6

    49.0

    2017

    1 324

    3 476

    383

    38.1

    11.0

    49.1

    2050

    1 267

    4 099

    1 056

    30.9

    25.8

    56.7

    LDCs

    2012

    365

    495

    31

    73.8

    6.3

    80.0

    2017

    397

    569

    36

    69.7

    6.3

    76.0

    2050

    586

    1 205

    126

    48.6

    10.4

    59.1

    LLDCs

    2012

    181

    250

    16

    72.4

    6.5

    78.9

    2017

    198

    287

    19

    69.1

    6.6

    75.7

    2050

    280

    597

    62

    46.9

    10.3

    57.2

    SIDS (UNCTAD)

    2012

    3

    8

    1

    45.7

    10.4

    56.0

    2017

    3

    8

    1

    43.2

    11.4

    54.6

    2050

    3

    10

    2

    35.2

    22.8

    58.0

    HIPCs (IMF)

    2012

    272

    323

    19

    84.1

    5.8

    89.9

    2017

    304

    379

    22

    80.1

    5.8

    85.9

    2050

    495

    931

    76

    53.1

    8.2

    61.4

    BRICS

    2012

    708

    2 103

    224

    33.7

    10.6

    44.3

    2017

    709

    2 179

    272

    32.5

    12.5

    45.0

    2050

    576

    2 213

    672

    26.0

    30.4

    56.4

    G20

    2012

    1 029

    3 149

    434

    32.7

    13.8

    46.5

    2017

    1 029

    3 249

    510

    31.7

    15.7

    47.4

    2050

    874

    3 307

    1 098

    26.4

    33.2

    59.6

    Table 2

    Age structure by gender and group of economies, 2017

    Group of economies

    Gender

    Population
    (Millions)

    Age class
    (Percentage)

    0-14

    15-24

    25-39

    40-64

    65-74

    75+

    World

    Female

    3 741

    25.3

    15.4

    22.4

    27.3

    5.7

    4.0

    Male

    3 808

    26.6

    16.1

    22.8

    26.7

    5.0

    2.8

    Developing economies

    Female

    3 043

    27.3

    16.4

    23.0

    26.0

    4.7

    2.7

    Male

    3 144

    28.3

    17.0

    23.1

    25.4

    4.2

    2.0

    Developing economies: Africa

    Female

    628

    40.2

    19.0

    20.5

    16.3

    2.6

    1.3

    Male

    627

    41.4

    19.4

    20.5

    15.6

    2.2

    0.9

    Developing economies: America

    Female

    324

    24.1

    16.7

    23.4

    26.9

    5.2

    3.7

    Male

    317

    25.8

    17.6

    23.9

    25.7

    4.5

    2.6

    Developing economies: Asia and Oceania

    Female

    2 091

    23.9

    15.5

    23.7

    28.7

    5.2

    3.0

    Male

    2 200

    25.0

    16.2

    23.8

    28.1

    4.7

    2.3

    Transition economies

    Female

    161

    18.6

    11.0

    22.9

    32.5

    7.8

    7.3

    Male

    146

    21.8

    12.8

    25.5

    30.9

    5.5

    3.5

    Developed economies

    Female

    536

    15.8

    11.2

    18.9

    33.2

    10.7

    10.3

    Male

    519

    17.1

    12.1

    20.0

    33.9

    9.8

    7.1

    Selected groups

    Developing economies excluding China

    Female

    2 360

    30.3

    17.8

    22.8

    22.9

    3.9

    2.3

    Male

    2 417

    31.3

    18.3

    23.0

    22.3

    3.4

    1.7

    Developing economies excluding LDCs

    Female

    2 539

    25.0

    15.7

    23.4

    27.8

    5.1

    3.0

    Male

    2 643

    26.1

    16.4

    23.7

    27.1

    4.5

    2.2

    LDCs

    Female

    503

    39.0

    19.7

    20.8

    16.6

    2.6

    1.3

    Male

    500

    40.2

    20.1

    20.4

    15.9

    2.3

    1.1

    LLDCs

    Female

    253

    38.5

    19.5

    20.9

    16.8

    2.7

    1.5

    Male

    251

    40.1

    20.1

    20.7

    15.8

    2.2

    1.1

    SIDS (UNCTAD)

    Female

    6

    27.4

    17.3

    22.1

    25.0

    4.9

    3.3

    Male

    6

    28.4

    18.0

    22.7

    24.3

    4.3

    2.3

    HIPCs (IMF)

    Female

    353

    42.5

    19.9

    19.6

    14.6

    2.3

    1.1

    Male

    351

    43.7

    20.3

    19.4

    13.8

    2.0

    0.9

    BRICS

    Female

    1 541

    21.7

    14.5

    23.6

    30.8

    5.9

    3.5

    Male

    1 618

    23.1

    15.3

    23.9

    29.8

    5.3

    2.5

    G20

    Female

    2 363

    20.8

    14.0

    22.5

    30.9

    6.9

    5.0

    Male

    2 426

    22.2

    14.8

    23.1

    30.4

    6.1

    3.4