Fertility and living standards Go forth and multiply a lot less The Economist 1 of 6 http www economist com node 14743589 print Fertility and living standards Lower fertility is changing the world for the better Oct 29th 2009 from the print edition SOMETIME in the next few years if it hasn t happened already the world will reach a milestone half of humanity will be having only enough children to replace itself That is the fertility rate of half the world will be 2 1 or below This is the replacement level of fertility the magic number that causes a country s population to slow down and eventually to stabilise According to the United Nations population division 2 9 billion people out of a total of 6 5 billion were living in countries at or below this point in 2000 05 The number will rise to 3 4 billion out of 7 billion in the early 2010s and to over 50 in the middle of the next decade The countries include not only Russia and Japan but Brazil Indonesia China and even south India The move to replacement level fertility is one of the most dramatic social changes in history It manifested itself in the violent demonstrations by students against their clerical rulers in Iran this year It almost certainly contributed to the rising numbers of middle class voters who backed the incumbent governments of Indonesia and India It shows up in rural Malaysia in richer emptier villages surrounded by mechanised farms And everywhere it is changing traditional family life by enabling women to work and children to be educated At a time when Malthusian alarms are ringing because of environmental pressures falling fertility may even provide a measure of reassurance about global population trends The fertility rate is a hypothetical almost conjectural number It is not the same as the birth rate which is the number of children born in a year as a share of the total population Rather it represents the number of children an average woman is likely to have during her childbearing 5 18 2011 2 11 PM Fertility and living standards Go forth and multiply a lot less The Economist 2 of 6 http www economist com node 14743589 print years conventionally taken to be 15 49 If there were no early deaths the replacement rate would be 2 0 actually fractionally higher because fewer girls are born than boys Two parents are replaced by two children But a daughter may die before her childbearing years so the figure has to allow for early mortality Since child mortality is higher in poor countries the replacement fertility rate is higher there too In rich countries it is about 2 1 In poor ones it can go over 3 0 The global average is 2 33 By about 2020 the global fertility rate will dip below the global replacement rate for the first time Modern Malthusians tend to discount the significance of falling fertility They believe there are too many people in the world so for them it is the absolute number that matters And that number is still rising by a forecast 2 4 billion over the next 40 years Populations can rise while fertility declines because of inertia which matters a lot in demography If because of high fertility in earlier generations there is a bulge of women of childbearing years more children will be born though each mother is having fewer children There will be more smaller families Assuming fertility falls at current rates says the UN the world s population will rise from 6 8 billion to 9 2 billion in 2050 at which point it will stabilise see chart 1 Behind this is a staggering fertility decline In the 1970s only 24 countries had fertility rates of 2 1 or less all of them rich Now there are over 70 such countries and in every continent including Africa Between 1950 and 2000 the average fertility rate in developing countries fell by half from six to three three fewer children in each family in just 50 years Over the same period Europe went from the peak of the baby boom to the depth of the baby bust and its fertility also fell by almost half from 2 65 to 1 42 but that was a decline of only 1 23 children The fall in developing countries now is closer to what happened in Europe during 19th and early 20th century industrialisation But what took place in Britain over 130 years 1800 1930 took place in South Korea over just 20 1965 85 Things are moving even faster today Fertility has dropped further in every South East Asian country except the Philippines than it did in Japan The rate in Bangladesh fell by half from six to three in only 20 years 1980 to 2000 The same decline took place in Mauritius in just ten 1963 73 Most sensational of all is the story from Iran When the clerical regime took over in 1979 the mullahs apparently believing their flock should go forth and multiply abolished the country s family planning system Fertility rose reaching seven in 1984 Yet by the 2006 census the average fertility rate had fallen to a mere 1 9 and just 1 5 in Tehran From fertility that is almost as high as one can get to below replacement level in 22 years social change can hardly happen faster No wonder the explosion on the streets of Iran this year seemed like a clash between two worlds 15 29 year olds one third of the population better educated and with different expectations against the established regime and the traditionalists Why has fertility fallen so fast so widely Malthus himself thought richer people would have more children and as any biologist will tell you animal populations increase when there is more food around To understand why wealthy people differ from well fed animals imagine yourself a dirt poor male peasant 50 years ago Your fields are in the middle of nowhere Your village has no school hospital or government services certainly no pensions Few goods come into it from outside though disease is rampant and security fragile Ploughing and reaping are done by hand But if the 5 18 2011 2 11 PM Fertility and living standards Go forth and multiply a lot less The Economist 3 of 6 http www economist com node 14743589 print harvest is normal you usually have enough to go round In these circumstances the benefit of an extra pair of hands to gather the harvest outweighs the cost of feeding an extra mouth which anyway falls on your wife more than you And when you can no longer work in the fields your children will be the only ones to look after you In such a society all the incentives point to having large families The abandoned hamlet Now imagine you are a bit richer You may have moved to a town or your village may have