UN: World population grows faster than expected, will reach 11 Bio. by 2100

[Tender Branson]

http://www.guardian.co.uk/global-development/2013/jun/13/nigeria-larger-population-us-2050

[politicus]

http://www.guardian.co.uk/global-development/2013/jun/13/nigeria-larger-population-us-2050

11 billion is likely too high a number to be managable combined with the full effects of climate change. Even with an optimistic prognosis for technological development. But some experts claim its managable at 12 bio. Lets hope they are right.

A lot of African nations would be higly unstable in this scenario. 

The UN prognosis with stabilization on 9-9,5 bio. around 2050 seems like aeons ago now.

[Franknburger]

I strongly doubt that the figures projected by the UN will be reached. Apparently, their projection is based on current fertility rates, but those rates are unlikely to stay that high in future.

High fertility is mostly a rural phenomenon and strongly determined by education and (lack of) social security. In the countryside, many children mean a higher chance of enough of them surviving to support their parents during their old age. The cost of having children is relatively low - food is home-grown, the house is crowded anyway but may be extended relatively easily if needed, the children can help with the harvest or gain some additional family income, etc., and there are enough relatives around to look after the children if the mother is busy with other activities. In the cities (slums), it is completely different. Food needs to be purchased at the market, the house cannot be expanded, clothing is more (and earlier in the child's life) an issue, etc. Suddenly, having another child becomes a financial issue.

The next factor is access to and quality of health services. As long as half of your children die before they are five years old (as they do in many rural parts of Africa) you better have a few more to ensure your old-age support. At a decent level of maternal and child health care, that motivation goes away - not immediately, but gradually.

Education - costly for the parents, but an investment that pays off, especially if you are already living in a city. Many parents quickly realise that it is better to have 2-3 well educated children that will earn a decent income from which they will pay for their parents' old age, than 6-8 that are all struggling themselves to survive and hardly have resources for supporting their parents.

Last but not least, there are alternative forms of old-age security developing - government or large-scale company pensions, but most importantly a variety of financial products, from life insurance and pension funds down to simple savings accounts. And in many cases, it is more economical to invest into one of these financial products than into another child to secure your old age.

All theory? I haven't looked it up, but I am pretty sure that in the 1980s, the projection would have been similar in its totals, but with India and Indonesia on the top of the list. However, between 1970 and 2005, the average fertility in India has gone down from 5,35 children per mother to 2.88. In Indonesia, it decreased from 4.78 to 2.56. The reasons - all of the above (urbanisation, improved access to health and education, emergence of financial products). Not to the extent that these two countries are in any way comparable to North American or European levels (if they were, they would also have similar reproduction rates), but enough to bring fertility down to a more or less sustainable level.
Or take Ghana, one of the "African tigers" with strong and steady economic growth over the last decade. The fertility rate has gone down from 7.04 in 1970 to 4.03 now. If economic and social development continues, they should be around 2.5 births / mother in around 25 years.

Most of the "high population growth" countries listed by the UN are ridden by economic problems, political instability and armed conflicts. If the situation prevails, the high fertility will go along with high mortality (in fact, the two almost always go hand in hand), resulting in a much slower population growth than predicted.
More likely, however, is an economic upturn after strong population growth. Remember the 1980s slogan "Even if every Chinese only drinks one bottle of Coke per year, it is still 1 billion bottles you can sell there". Global companies just cannot afford to leave out such highly-populated countries - first for essential products (food, soap etc.), than a few consumer goods plus stuff like bicycles, then comes the first motor vehicle assembly, etc. Results: Urbanisation, (public revenue for) better education & health, a market for financial service providers - and the fertility rate drops.

A high-population growth country must be pretty mismanaged to be left out - neither Chinese Communism, nor India's and Indonesia's corruption and public sector mismanagement did scare off international investors in the 1980s and 1990s. Somalia may actually be such a case, but the other "top growth countries", namely Nigeria, DR Congo, Ethiopia, Uganda and Tanzania all range between manageable (Nigeria, DR Congo) to pretty low (Ethiopia, Uganda) investment risk and problems.  Ethiopia, e.g., has seen quite some foreign investment and economic development over the last years. Its fertility rate has decreased from 6.83 in 1985 to 4.8 now, and I am pretty confident it will continue to fall further.

 

[Landslide Lyndon]

I strongly doubt that the figures projected by the UN will be reached. Apparently, their projection is based on current fertility rates, but those rates are unlikely to stay that high in future.

High fertility is mostly a rural phenomenon and strongly determined by education and (lack of) social security. In the countryside, many children mean a higher chance of enough of them surviving to support their parents during their old age. The cost of having children is relatively low - food is home-grown, the house is crowded anyway but may be extended relatively easily if needed, the children can help with the harvest or gain some additional family income, etc., and there are enough relatives around to look after the children if the mother is busy with other activities. In the cities (slums), it is completely different. Food needs to be purchased at the market, the house cannot be expanded, clothing is more (and earlier in the child's life) an issue, etc. Suddenly, having another child becomes a financial issue.

The next factor is access to and quality of health services. As long as half of your children die before they are five years old (as they do in many rural parts of Africa) you better have a few more to ensure your old-age support. At a decent level of maternal and child health care, that motivation goes away - not immediately, but gradually.

Education - costly for the parents, but an investment that pays off, especially if you are already living in a city. Many parents quickly realise that it is better to have 2-3 well educated children that will earn a decent income from which they will pay for their parents' old age, than 6-8 that are all struggling themselves to survive and hardly have resources for supporting their parents.

Last but not least, there are alternative forms of old-age security developing - government or large-scale company pensions, but most importantly a variety of financial products, from life insurance and pension funds down to simple savings accounts. And in many cases, it is more economical to invest into one of these financial products than into another child to secure your old age.

All theory? I haven't looked it up, but I am pretty sure that in the 1980s, the projection would have been similar in its totals, but with India and Indonesia on the top of the list. However, between 1970 and 2005, the average fertility in India has gone down from 5,35 children per mother to 2.88. In Indonesia, it decreased from 4.78 to 2.56. The reasons - all of the above (urbanisation, improved access to health and education, emergence of financial products). Not to the extent that these two countries are in any way comparable to North American or European levels (if they were, they would also have similar reproduction rates), but enough to bring fertility down to a more or less sustainable level.
Or take Ghana, one of the "African tigers" with strong and steady economic growth over the last decade. The fertility rate has gone down from 7.04 in 1970 to 4.03 now. If economic and social development continues, they should be around 2.5 births / mother in around 25 years.

Most of the "high population growth" countries listed by the UN are ridden by economic problems, political instability and armed conflicts. If the situation prevails, the high fertility will go along with high mortality (in fact, the two almost always go hand in hand), resulting in a much slower population growth than predicted.
More likely, however, is an economic upturn after strong population growth. Remember the 1980s slogan "Even if every Chinese only drinks one bottle of Coke per year, it is still 1 billion bottles you can sell there". Global companies just cannot afford to leave out such highly-populated countries - first for essential products (food, soap etc.), than a few consumer goods plus stuff like bicycles, then comes the first motor vehicle assembly, etc. Results: Urbanisation, (public revenue for) better education & health, a market for financial service providers - and the fertility rate drops.

A high-population growth country must be pretty mismanaged to be left out - neither Chinese Communism, nor India's and Indonesia's corruption and public sector mismanagement did scare off international investors in the 1980s and 1990s. Somalia may actually be such a case, but the other "top growth countries", namely Nigeria, DR Congo, Ethiopia, Uganda and Tanzania all range between manageable (Nigeria, DR Congo) to pretty low (Ethiopia, Uganda) investment risk and problems.  Ethiopia, e.g., has seen quite some foreign investment and economic development over the last years. Its fertility rate has decreased from 6.83 in 1985 to 4.8 now, and I am pretty confident it will continue to fall further.

 

Very interesting. Thanks for the analysis.

[Tender Branson]

The reports and data are now online:

http://esa.un.org/unpd/wpp/Documentation/publications.htm

[Franknburger]

The reports and data are now online:

http://esa.un.org/unpd/wpp/Documentation/publications.htm

Some of them, at least (I still get various error / "server maintenance" messages on individual pages).

A first methodological assessment:

1. Instead of a causality analysis as per my previous post, they use a Bayesan statistical model to estimate each country's fertility and mortality trends. Essentially, several hundreds of random walk simulations, starting at a country's current levels. The results of the individual simulations are then aggregated into probability estimates (the basic methodology that is also used, e.g., by Nate Silver on FiveThirtyEight for calculating election probabilities). The random walk paths are determined by historic global trends, so they capture a lot of the underlying causal relations that I have outlined in my previous post. In addition,  they also try to fit the random walk paths to county-specific historic data. So far, so good, and results are looking pretty plausible to me for those countries that had a steady socio-demographic development (e.g. Ghana).
However, the problems start when the available country data shows atypical fluctuations, that are most likely caused by armed conflict and/or external shocks (e.g. DR Congo), but may also relate to questionable basic data (for Nigeria, e.g., there is no census or birth registration, but only survey data available). In such cases, their model tends to predict very flat fertility curves, i.e. a fertility that remains virtually constant at current high levels.

2. The same approach is applied to mortality projections. However, as I said in my previous post, fertility and mortality are not independent of each other, but closely correlated. Let's take the case of Niger. Fertility is very high (7.02 births per woman in 2006, last data that is available) and has hardly changed since the 1960s. This makes sense - at 17%, Niger is one of the least urbanised countries in the world. Accordingly, the life expectancy at birth is very low (male 52.5, female 55 years, rank 201 out of 220 world countries).  Their model predicts quick and steady improvement up to almost 70 years female life expectancy at birth by 2050. Great, and I hope this prediction comes true - but that implies strong urbanisation and massive improvement of health services, which over the same time should send the fertility rate down much faster than they are predicting.

3. The key to increasing life expectancy in the Third World is reducing infant and child mortality. This, however, is also a major determinant of birth rates. There is tons of statistical analysis available, including research on Pre WW I Europe, 20th century trends in various industrialised countries, post 1950 trends in Latin America, and recent research on India and several African countries. They unanimously confirm a positive correlation between fertility and child mortality, but differ on the coefficient. It may, however, rank as high as 0.5, i.e. for every child that survives to the age of six, half a child less is born, and I think such figure may be quite plausible for high child mortality/ high fertility countries in Africa. As such, reduced mortality (as assumed in the UN model) should directly and quickly send down fertility rates - a relation that is not covered by the projection.

4. The documentation is not very clear in this point, but it appears that the projections are being based on standardised Life Tables that are modified according to geographic region, but not according to country. Moreover, the tables only start at the age of 20. This suggests to me that country-specific differences in child mortality are not reflected in the projections.  In other words: The model seems, for example, to assume that as many Ghanaian new-born girls will come into reproduction age as Niger or Nigerian ones. However, child mortality is much lower in Ghana than in Nigeria or Niger - one of the reasons for lower fertility in Ghana. As such, the reproduction rate in high mortality/ high-fertility countries is exaggerated by some 7-10%. Since we are talking 3-4 reproduction cycles until 2010, and an exponential relation, such a seemingly minor exaggeration quickly adds up into a sizeable overestimate.

Bottom line: The projections' merit is to draw attention to anomalies in country-specific population trends, and puts some countries into the spotlight that are otherwise easily overlooked (e.g. Niger, Uganda). There absolute numbers, however, should be taken with more than just one grain of salt.

[Franknburger]

Dug into their data a bit further. For already quite some time, most European countries, as well as Australia, the USA, Canada, Japan and South Korea have fallen below the 2.1 births / women reproduction level that is needed to maintain population constant. It is also not surprising that China, with their "1 child policy", have joined them. But there are a quite a few more countries in the club that I had not expected to see there:

Bahrain (2008: 2.06)
Barbados (2007: 1.83) (in fact, most of the Caribbean is in that range, but listing every island would make the list quite long)
Brazil (2008: 1.84)
Brunei Darussalam (2008: 1,76)
Costa Rica (2009: 1.90)
Cuba (2010: 1.68)
North Korea (2008: 2.01)
Iran (2008: 1.89)
Jamaica (2006: 1.95)
Lebanon (2001; 1.89)
Mauritius (2010: 1.46)
Myanmar (2006: 1.90)
Qatar (2010: 2.02)
Singapore (2010: 1.27) (that is less than in Germany !)
Thailand (2009: 1.43) (less than Austria)
Turkey (2010: 1.99)
Uruguay (2007: 1.96)
Vietnam (2009: 2.00)

Quite a lot of Muslim countries in the list - religion is obviously not a determining factor.

While we are at religion, let's compare a few European Protestant and Catholic countries:

Iceland:            2.19
Ireland:            2.13
France:             2.07
Sweden:           1.98
Norway:           1.97
Denmark:         1.87
Netherlands:     1.81
Estonia:            1.64
Lithuania:         1.55
Italy:                1.43
Spain               1,39
Poland:            1.38
Slovakia:          1.38
Portugal:          1.35
Latvia:             1.17 (that's the lowest inside the EU)

Obviously, nobody outside Ireland is listening to the Pope anymore ...

[memphis]

Hopefully Africa can get its sh!t together. They're pretty much the only place in the world still popping out babies pre-industrial style. I'd very much rather not see extremely massive famine and disease wipe out Africans by the tens of millions. Nature has its own way of handling too many people and it's less pretty than simple contraception.

[Franknburger]

Hopefully Africa can get its sh!t together. They're pretty much the only place in the world still popping out babies pre-industrial style. I'd very much rather not see extremely massive famine and disease wipe out Africans by the tens of millions. Nature has its own way of handling too many people and it's less pretty than simple contraception.

There are a number of very fertile countries outside Africa - Afghanistan, Laos, Palestine territories, Yemen, Honduras, Bolivia, a number of Pacific island states, and even Syria (though that will most likely have changed in the meantime).

But, yes, Africa stands out in terms of the number of high-reproduction countries. However, you need to look at each country individually. A number of African states are doing pretty well in terms of reducing fertility, and improving health and education (which go hand in hand): Senegal, Ghana, Ethiopia, Rwanda, Lesotho, Botswana, Namibia, Benin, even Togo (in spite of their political instability) have reduced the average number of children  below five, in some cases already below four. South Africa is down to 2.5.

And there are the "forgotten corners" - Niger, Chad, etc. - land-locked, few natural resources, hardly urbanised, and now also under Al Kaida pressure - they can't do it alone, they need international assistance. Countries like Tanzania, Zambia and Malawi have virtually lost a whole generation (including well-educated doctors, teachers, managers etc.) to HIV/AIDS, so I think its fair to postpone judgement until they have recovered.

Yeah, and then you have countries that should have gotten their sh..t together long ago. With all their oil wealth, it is appalling how underdeveloped Angola and Nigeria are (I could not trust my eyes this afternoon when checking Nigeria's child mortality rate!). And Kenya and Zimbabwe, once the economic powerhouses of East Africa, have effectively lost two decades to mismanagement, corruption and tribalism.