Posts Tagged ‘Total fertility rate’

Population Implosion? Even US fertility rates are at lower than replacement level

June 8, 2014

In Iran the Ayatollah Khamenei has announced his 14 point plan (or directive) to try and revive the fertlity rate which is at a potentially catastrophic low. In the US, Hispanic fertility rates have – in recent times – held the fertility rate up just above the replacement level of 2.1. In China the one-child policy has been withdrawn as population has reached its peak and will now decline significantly. In country after country, fertility rates are lower than the replenishment rate. In half the states in India the rate is already below 2.1. By 2050 the total Indian population will start to decline. Generally improvement in living standards with more attention to women’s rights are accompanied by a sharp decline in fertility rates. Now however, the recession is being blamed for the decline in the US.

Till 2100 the main demographic challenge is increasingly going to be the long term decline in fertility and the increasing proportion of the “aged” relative to the working population.

US TFR - Washington Examiner

US TFR – Washington Examiner

Washington Examiner:

U.S. fertility is not recovering from the financial crisis — and demographers aren’t sure why. The fertility rate fell to a record low 62.9 births per 1,000 women aged 15-44 in 2013, according to the National Center for Health Statistics.

The total number of births, at 3.96 million, inched up by a mere 4,000 from 2012, the first increase since the financial crisis. But the total fertility rate, or TFR, the average number of children a woman would have during her child-bearing years, fell to just 1.86, the lowest rate in 27 years. TFR is considered the best metric of fertility. A TFR of 2.1 represents a stable population, with children replacing parents as they die off.

Demographers expected the fertility rate to fall during recession, as financially strapped families put off childbearing. But what has surprised some demographers is both the depth of the decline and the fact that fertility has continued to drop even over the course of the country’s five years of slow but steady recovery. The rate has fallen steadily each year since 2007, when it stood at 2.1 …….. 

One foreseen factor behind the dropoff in childbearing is the rapid decline in Hispanic-American fertility.

 For several decades, high Hispanic childbearing has been driving U.S. population growth. White fertility has been under the 2.1 replacement rate for decades, and ranged from 1.7 to 1.9 in the 2000s. The TFR for black Americans first fell below 2.1 in the early 2000s. 

But the number of children per Hispanic-American woman has plummeted from just under three in 1990 and 2.7 as recently as 2008 to 2.19 in 2012, just above the replacement rate.

That decline has been mirrored in other Hispanic countries. Mexico’s TFR has fallen precipitously, from 6.7 in 1970 to 2.2 in 2012, according to the World Bank. A similar decline has taken place in El Salvador, and to a lesser extent Honduras and Guatemala, all three prominent countries of origin for American Hispanics. ….

 

Waves of aging

December 15, 2013

The aging of the world is not news, but visualising the change is done very well here:

Population By Age, Japan

Population By Age, Japan

Population By Age, U.S.

Population By Age, U.S.

Not all countries are getting older. Many developing countries still have high fertility rates, and children account for a huge share of the people in those countries. (Typically, fertility rates don’t start falling until countries hit a certain stage of economic development.)

When you look at the whole world, you see a blend of these two trends — the population of the globe is aging, on average, but there are still far more children than old people.

World Population Breakdown By Age

World Population Breakdown By Age

 

By 2100, 8 million could be over 100 years old

November 13, 2013

The 2012 review of the UN’s World Population Prospects was released in August this year.

World Population Prospects 2012 (pdf – 3.53Mb)

Charts are still – presumably – being prepared since the interactive charts from the 2010 review are no longer available on the UN site and have not yet been replaced by new charts.

The basic picture is still of fertility rates decreasing steadily with the medium scenario giving a world population stabilising at about 10.8 billion around 2100. Chinese population is just about at its peak and will now be reducing till 2100. Indian population will reach its peak around 2060 and then start declining. African population will reach its peak only around 2100.

WPP12 Fertlity

WPP12 Fertlity

There is a massive amount of data and projections, and the interesting thing about demographic forecasts done on this scale is that the “inertia” is high. Consequently much of the “forecast” is inevitable and the key parameter is the fertility rate. In 1953, 99.9% of the world population exhibited a fertility rate greater than 2.1 children per woman (the static population replenishment rate). Now in 2013, 49% of the world’s population have a fertility rate lower than 2.1. Half the world’s population is already shrinking. By 2100 this will be 81% and the world population as a whole will be shrinking.

A significant proportion of those under ten years old today will still be around in 2100. Today about 20% of the world population is under 10 years old ( approximately 1,400 million). In 2100 around 8% of 10.8 billion will be over 80 years old. Assuming that say 3% are older than 87 years, it would mean that 320 million (or 23% of those under 10 or about 5% of everybody) living today will still be around in 2100. Today about 14% of the world’s population is over 60 and about 2% are over 80. By 2100, 35% will be over 60 and about 8% over 80 years old. The 950 million over 60 today will become 3,800 million by 2100.

More than 800 million people will be over 80 and I would estimate that around 1% of these  – or 8 million – could be over 100 years old!

Bloomberg (2012)Unicharm Corp.’s sales of adult diapers in Japan exceeded those for babies for the first time last year.

Just the demographics is changing the make up of the world and its genetic mix.

WPP12 population mix

WPP12 population mix

The human genetic pool in 2100 will be geographically placed 40% in Africa, 40% in Asia with the remaining 20% spread between The Americas, Oceania and Europe. And while there will be some migration and genetic mixing, this basic distribution will be maintained. Moreover, fertility rates will be stable and close to (even if just under) 2.1 in all regions. Median age is also on the way up world-wide.

WPP12 median age

WPP12 median age

Life expectancy is rising across the world:

The twentieth century witnessed the most rapid decline in mortality in human history. In 1950-1955, life expectancy at the world level was 47 years and it had reached 69 years by 2005-2010. Over the next 40 years, life expectancy at birth at the global level is expected to reach 76 years in 2045-2050 and 82 years in 2095-2100 (table III.1 and figure III.1). The more developed regions already had a high expectation of life in 1950-1955 (64.7 years) and have since experienced further gains in longevity. By 2005-2010 their life expectancy stood at 76.9 years, 10 years higher than in the less developed regions where the expectation of life at birth was 67.0 years. Although the gap between the two groups is expected to narrow between 2005 and mid-century, in 2045-2050 the more developed regions are still expected to have considerably higher life expectancy at birth than the less developed regions (82.8 years versus 74.8 years). Throughout 2010-2100, systematic progress against mortality is further expected to increase life expectancy at birth up to 88.9 years in the more developed regions and 80.8 years in the less developed regions thereby further reducing the gap in mortality between the two groups.

What occurs to me also is that famine, disease, war and the effects of natural catastrophes are becoming less and less relevant demographically. But I shall return to that subject in another post.

India’s plummeting birth rates illustrate the coming population decline

May 9, 2013

Fertility rates are dropping sharply across the world and simple arithmetic tells us that by 2100 world population will be steady or declining slightly. In fact, rather than facing a population explosion and food shortages we will be facing the demographic challenges of a stable or declining population together with an increase in longevity. A new flexibility in the patterns of working will be needed as the populations in work reduce in proportion to those beyond retirement age. Retirement age itself will have to increase.

Yet it seems to me that the utterly alarmist, Malthusian, catastrophe scenarios for world population put forward in the 1970’s and 80’s by the Club of Rome, Ehrlich and other doom-mongers still prevail as “conventional wisdom” – even though it has long been established that their basic assumptions were plain wrong. For some reason environmentalists are the most ardent deniers of what the arithmetic says. They are the first to proclaim the dangers of population explosions yet are extremely loth to abandon catastrophe scenarios they have espoused when they are shown to be exaggerated or false.

I was therefore glad to see the subject getting attention in GeoCurrents where Martin W Lewis addresses and presents the sharply falling fertility rates around the world and in the various States in India. His maps are particularly well put together. The average fertlity rate in India is now down to 2.5 but many of the States fall well below the “replacement rate” of 2.2. The variation of fertility rates is impacted by the “usual suspects”; GDP, female literacy, proportion of urban dwellers, life expectancy, the Human Development Index (HDI) and the availability of electricity. But as Lewis shows there is also a striking correlation between fertility and TV ownership (seems plausible) and between fertility rates and the exposure of women to the media (also very plausible).

India’s Plummeting Birthrate: A Television-Induced Transformation?

…. It can be deceptive, however, to view India as an undivided whole. As shown on the map posted here, fertility figures for half of India are actually below replacement level. Were it not for the Hindi-speaking heartland, India would already be looking at population stabilization and even decline. All the states of southern India post TFR figures below 1.9. A number of states in the far north and the northeast boast similarly low fertility levels, including West Bengal, noted for its swarming metropolis of Calcutta (Kolkata).

(from GeoCurrents)

India’s geographical birthrate disparities, coupled with the country’s admirable ability to collect socio-economic data, allow us to carefully examine ideas about fertility decline. The remainder of this post will do so through cartography, comparing the Indian fertility-rate map with maps of other social and economic indicators. ……. 

……

Some scholars have argued that recent fertility decreases in India and elsewhere in the Third World are more specifically linked to one technological innovation: television. The TV hypothesis is well-known in the field, discussed, for example, in the LiveScience article on the African population explosion mentioned above. In regard to India, Robert Jensen and Emily Oster argue persuasively that television works this magic mostly by enhancing the social position of women. As they state in their abstract:

This paper explores the effect of the introduction of cable television on women’s status in rural India. Using a three-year, individual-level panel dataset, we find that the introduction of cable television is associated with significant decreases in the reported acceptability of domestic violence towards women and son preference, as well as increases in women’s autonomy and decreases in fertility. We also find suggestive evidence that exposure to cable increases school enrollment for younger children, perhaps through increased participation of women in household decision-making. We argue that the results are not driven by pre-existing differential trends.

As it turns out, the map of television ownership in India does bear a particularly close resemblance to the fertility map. Two anomalously low-fertility states with low levels of female education, Andhra Pradesh and Jammu and Kashmir, score relatively high on TV penetration, as does West Bengal, which lags on several other important socio-economic indicators. The correlation is far from perfect: Mizoram ranks higher on the TV chart than its fertility figures would indicate, whereas Odisha and Assam rank lower. Odisha and Assam turn out to be a bit less exceptional in a related but broader and more gender-focused metric, that of “female exposure to media.” These figures, which include a television component, seem to provide the best overall correlation with the spatial patterns of Indian fertility.

(from GeoCurrents)

“Bearing children has largely become the province of the lower classes”

May 2, 2013

The Daily Mail runs an article today about why the middle class are not breeding any more. It is not difficult to get a faint whiff of eugenics. But I can’t help feeling that some level of eugenics is not necessarily all bad as we move from natural selection to a world where artificial selection (IVF, surrogacy, sperm banks etc.) is increasing. And of course, even the availability of abortion on demand is in itself a form of selection.

  • Educated women deferring motherhood for so long they’re no longer fertile
  • Bearing children ‘has largely become the province of the lower classes’ 
  • TV historian Dr Lucy Worsley is poster girl for intentionally childless women

…. as author and demographic expert Jonathan Last observes in his controversial book What to Expect When No One’s Expecting:

‘The bearing and raising of children has largely become the province of the lower classes. It’s a kind of reverse Darwinism where the traditional markers of success make one less likely to reproduce.’

If “lower class” were a genetic trait then the middle and higher classes should fear extinction in due course. Fortunately “class” is just relative and subjective so no matter what the demographics are, distinctions of class will be introduced into any population that exists. But what is more interesting to consider is the fact that women with a higher level of education (which says nothing about native intelligence) have fewer children. This seems to be a global phenomenon. Data from 2010 in the extract below.

The full table is here. Primary School Enrollment and Total Fertility Rates, Latest Year (2000-2010)

Primary School Enrollment and Total Fertility Rates for Selected Countries, Latest Year 2000 – 2010

Rank Country

Primary School Enrollment

Total Fertility Rate

Percent

Number of children
per woman

1 Japan

100.0

1.3

2 Spain

99.8

1.5

3 Iran

99.7

1.8

4 Georgia

99.6

1.6

5 United Kingdom

99.6

1.9

181 Equitorial Guinea

53.5

5.3

182 Guinea-Bissau

52.1

5.7

183 Djibouti

40.1

3.9

184 Sudan

39.2

4.2

185 Eritrea

35.7

4.6

Note: Rankings are based on a list of 185 countries for which primary enrollment data are available.
Source: EPI from UNESCO

Fertility rates tend to be highest in the world’s least developed countries. When mortality rates decline quickly but fertility rates fail to follow, countries can find it harder to reduce poverty. Poverty, in turn, increases the likelihood of having many children, trapping families and countries in a vicious cycle. Conversely, countries that quickly slow population growth can receive a “demographic bonus”: the economic and social rewards that come from a smaller number of young dependents relative to the number of working adults.

For longer term population stability the goal is to reach replacement-level fertility, which is close to 2 children per woman in places where mortality rates are low. Industrial countries as a group have moved below this level. Some developing countries have made progress in reducing fertility, but fertility rates in the least developed countries as a group remain above 4 children per woman.

The trends with secondary education are also very clear:
Female Secondary Education and Total Fertility Rates

Of course the level of development in a country dominates and fertility rates around the world are reducing and converging. Whether this trend will continue even when all female children enjoy secondary education remains to be seen. The UK case where nearly all children do get secondary education would suggest that those with higher (university) education continue to show a declining fertility. But the real test of this hypothesis will only come when education levels around the world have equalised and fertility rates all lie around the same level.

So is the human population “dumbing down”? Not really. Education level is not intelligence. To what extent intelligence is a hereditary trait is uncertain. While it would seem that evolution should favour increasing intelligence, even this is not crystal clear. It is certainly a perception I have that “successful” people tend to be more intelligent but high intelligence does not ensure success. And success in life correlates with wealth but not so well with number of offspring.  “Success”, however we define it,  is not a genetic trait. There have been some suggestions that there may be some optimum level of intelligence for the genetic success of the species and that hunter-gatherers were actually somewhat more intelligent than we are now. Perhaps humans can be “too clever by half”!

But for some time to come, as the developing world catches up with the developed world, we can surely conclude that less-educated parents will have the higher fertility. Whatever that may mean for the long term evolution of humans, and that will be the result of the level to which we intentionally apply genetic selection.

Related: “Selection” lies in the begetting and evolution is just a result


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