Friday 14 December 2012

The meaning of statistics - national median age


From Wikipedia - Median age by country circa 2010.

Monaco 48.9 
Japan 44.6
Italy 44.3
Germany 43.7
Jersey 43.4
Hong Kong 42.8
Guernsey 42.7
Austria 42.6
Finland 41.6
Greece 42.2
San Marino 42.1
Slovenia 42.1
Belgium 42.0
Sweden 41.7
Bermuda 41.6
Bulgaria 41.6
Spain 41.5
Liechtenstein 41.4
Hungary 41.3
Switzerland 41.3
Croatia 41.2
Serbia 41.1
Netherlands 40.8
Denmark 40.7
Canada 40.7
United Kingdom 40.5
Isle of Man 40.4
Czech Republic 40.4
Latvia 40.4
Bosnia and Herzegovina 40.3
Estonia 40.2

Andorra 39.9
Saint Barthelemy 39.8
Virgin Islands, U.S. 39.8
Norway 39.7
Malta 39.7
France 39.7
Portugal 39.7
Lithuania 39.7
Ukraine 39.7
Singapore 39.6
Luxembourg 39.3
Belarus 38.8
Georgia 38.8
Russia 38.5
Cayman Islands 38.4
Saint Helena 38.2
Poland 38.2
Romania 38.1
Aruba 38.0
Korea, South 37.9
Cuba 37.8
Slovakia 37.3
Montenegro 37.2
Faroe Islands 37.1
Taiwan 37.0
New Zealand 36.8
United States 36.9
Puerto Rico 36.7
Barbados 36.2
Macau 35.6
Ireland 35.4
Iceland 35.4
Macedonia 35.4
Saint Pierre and Miquelon 35.2
China 35.2
Moldova 35.0

Cyprus 34.5
Netherlands Antilles 34.1
Korea, North 33.9
Thailand 33.7
Uruguay 33.7
Greenland 33.5
Gibraltar 33.1
Anguilla 33.0
British Virgin Islands 32.6
Trinidad and Tobago 32.6
Palau 32.4
Mauritius 32.3
Seychelles 32.0
Armenia 31.9
Chile 31.7
Saint Kitts and Nevis 31.5
Sri Lanka 31.3
Cook Islands 31.2
Qatar 30.8
Saint Martin 30.8
Bahrain 30.4
Saint Lucia 30.3
Dominica 30.3
Argentina 30.3
United Arab Emirates 30.2
Albania 30.2
Antigua and Barbuda 30.0

Bahamas, The 29.9
Kazakhstan 29.9
Tunisia 29.7
French Polynesia 29.5
Saint Vincent and the Grenadines 29.5
Lebanon 29.4
Northern Mariana Islands 29.3
Guam 29.3
Israel 29.3
Montserrat 29.1
New Caledonia 29.0
Brazil 28.9
Turks and Caicos Islands 28.0
Azerbaijan 28.5
Costa Rica 28.4

World 28.4 

Suriname 28.3
Grenada 28.2
Brunei 28.1
Turkey 28.1
Indonesia 27.9
Wallis and Futuna 27.9
Iran 27.6
Colombia 27.6
Vietnam 27.4
Panama 27.2
Algeria 27.1
Mexico 26.7
Burma 26.5
Morocco 26.5
Kuwait 26.4
Peru 26.4
Kosovo 26.3
Maldives 25.9
India 25.9
Fiji 25.8
Mongolia 25.8
Venezuela 25.8
Ecuador 25.3
Dominican Republic 25.2
Uzbekistan 25.2
Malaysia 25.1

Paraguay 24.9
Turkmenistan 24.8
South Africa 24.7
Kyrgyzstan 24.7
Vanuatu 24.6
Bhutan 24.3
Libya 24.2
Egypt 24.0
Oman 23.9
Jamaica 23.9
El Salvador 23.9
Tuvalu 23.9
Guyana 23.6
Bangladesh 23.5
American Samoa 23.4
Tonga 22.7
Philippines 22.7
Lesotho 22.6
Nicaragua 22.5
Cambodia 22.5
Micronesia, Federated States of 22.4
Cape Verde 22.3
Timor-Leste 22.2
Tajikistan 22.2
Bolivia 22.2
Botswana 22.0
Kiribati 22.2 21.4
Nauru 22.0
Samoa 21.8
Jordan 21.8
Saudi Arabia 21.6
Papua New Guinea 21.6
Marshall Islands 21.5
Syria 21.5
Namibia 21.4
Djibouti 21.4
Pakistan 21.2
Nepal 21.2
Ghana 21.1
West Bank 20.9
Belize 20.7
Honduras 20.7
Iraq 20.6
Haiti 20.5
Western Sahara 20.1
Swaziland 20.1
Solomon Islands 20.0

Guatemala 19.7
Laos 19.5
Cote d'Ivoire 19.4
Guinea-Bissau 19.4
Cameroon 19.3
Sudan 19.3
Mauritania 19.3
Central African Republic 19.1
Nigeria 19.1
Sierra Leone 19.0
Equatorial Guinea 19.0
Comoros 18.9
Togo 18.9
Senegal 18.7
Gabon 18.6
Rwanda 18.6
Guinea 18.5
Eritrea 18.5
Liberia 18.4
Tanzania 18.3
Madagascar 18.1
Angola 18.0
Gambia, The 18.0
Afghanistan 18.0
Zimbabwe 17.8
Somalia 17.6
Gaza Strip 17.5
Mozambique 17.5
Sao Tome and Principe 17.5
Benin 17.3
Mayotte 17.3
Zambia 17.2
Malawi 17.1
Ethiopia 16.8
Burkina Faso 16.8
Congo, Republic of the 16.9
Burundi 16.8
Chad 16.6
Congo, Democratic Republic of the 16.5
Yemen 16.4
Mali 16.2
Niger 15.2
Uganda 15.0



I find this a fascinating table, illustrative of the whole way in which statistics can throw light on things, but only with contextual understanding: the numbers qua numbers are meaningless.

 I reflect that the nations above the world average media age represent (in broad terms) the past, whereas those below media age represent the future.

And what an incredible number of nations there are!


Reflecting that the median age means that half the population are above that number, I recognize that the highest median ages are far higher than any society in world history. Most of these populations are mostly infertile, and this trend will increase for quite a while.

Equally, or more, significantly, the very low median ages of other populations mean that most of their population is fertile, and the proportion will tend to increase for a while.


The astonishingly low median age of some places means that absolute poverty, in the traditional sense, has almost disappeared - since in the past societies consisting of such high proportions of children were not viable (children being, naturally, the first to die of starvation, disease, violence) - these societies must, therefore, be being kept alive from external interventions.

The astonishingly low median age of some societies means that they are societies of (a very high proportion of) adolescents, of teenagers, and we know how such societies are likely to behave - especially if allowed to run themselves: they are gangs, they are violent, they are predatory etc.


Knowing a bit about trends, we can see how few societies in the world are stable and self-sustaining - since those of very high and low median age are off-the-map so far as world history goes; while many of the middling societies (which have what seems like a good median age) are actually simply in transition either going up or downwards: populations either collapsing into infertility, or growing in their unproductive parts, sustained by external inputs.


So much! So much richness of inference from a mere list of averages!

All available, free, in the public domain, to many hundreds of millions of people.

All incomprehensible, all ignored, all might as well be invisible, might as well not exist...



Ben said...

Hi Bruce,

By "off-the-map so far as world history goes"

Do you mean that these are relatively new countries and therefore the likelihood of them being around in the future is diminished?

Bruce Charlton said...

I mean unprecedented in their age structure.

Matthew C. said...

Bruce, I would be very interested to hear your comments on the current debt-based financial system, central banks, their actions since 2008 and the sustainability of this system over the next 5-20 years, in your estimation.

dearieme said...

What do you suppose the median age was in England in, say, 1300, 1400 .... 1900?

A society in which women bear lots of children, most of whom die in infancy, is man's usual lot, is it not?

Bruce Charlton said...

@dearieme - the short answer is that I do not know; but obviously you cannot have a median age of fortysomething when that is not much less than the life expectancy.

Like any statistic, median age in and of itself means nothing - it is the context which generates the meaning. It is more of a stimulus to reflection, a constraint on things.

For example, 99.99 percent of commentary on the Israel Gaza conflict (and the possibilities for political solutions etc) is rendered meaningless by the median age of Gaza; doubly so when this is combined with Richard Lynn's estimates of general intelligence; trebly so when it is considered that this population is being supplied with ready to fire rockets.

On the other hand, as I wrote in a previous post - none of these statistics are really necessary if people use their perceptions and experience and common sense.

dearieme said...

Talking about numbers, and given the recent hoo-ha about the census, here's a question to which I have only recently discovered the answer.

When was the first census of Annandale?

Andrew Beane said...

This is very interesting. I would love to see this list put side by side with a list of per capita incomes by country

Bruce Charlton said...

@AB - it is pretty much inverse, isn't it - which means that most of the world's fertility is accidental, unplanned, and (in a sense) unwanted - since the richer people become the fewer children they have.

The exception comes with devout adherents of certain religions (mostly the monotheisms: Judaism, Christianity, Islam) - these are the only groups that exhibit deliberate, strategic high fertility.