The Demographic Time Bomb: How Our Assumptions About Global Population Are About to Go Bang!

The Demographic Time Bomb: How Our Assumptions About Global Population Are About to Go Bang!

It is a truth universally acknowledged that any article, blog or book about population growth should start with Thomas Malthus.  This blog discusses a paradigm shift in world population – one which may finally put to bed the theories of the Rev Malthus, although that is far from the most important of the implications.

But let’s begin with Malthus. His Essay on the Principle of Population (first published in 1798) argued that there is a natural tendency for population to increase rapidly, and that population is held in check mainly by negative factors: hunger, disease and war. He went on to argue in later editions that preventive checks, such as later marriages, could ensure a higher standard of living, and increase economic stability.

At the time of the Essay’s publication, the population of the world is estimated to have been one billion.  Today, the world’s population is over 7 billion.  Over that period, the theories of Malthus have been kept at bay by rising living standards leading to longer life expectancy, reductions in infant (and maternal) mortality, near-eradication of many serious infectious diseases through vaccination and immunisation, better sanitation, and safer working conditions.  The spurt in world population began in Europe and the USA, spreading to the rest of the world.  As countries and regions have developed economically, they have acquired the means to ensure a better, healthier and safer life for their people.

The two centuries of rapid population growth have inspired various neo-Malthusian prophecies of doom – initially warnings of hunger and disease; and more recently warnings of the danger of exhausting the earth’s finite natural resources.  Population has stubbornly continued to rise, and so have living standards, with billions being lifted out of absolute poverty in the last 30 years, in spite of the warnings of imminent doom.  The neo-Malthusians have so far been proved wrong.

Checkmate for Malthus

This argument might continue as we move through the 21st century.  But a new book calls into question the most fundamental – and hitherto unchallenged – part of Malthusian theory.

Whilst the world’s growing population bears witness of the ability of humankind to keep at bay the checks of hunger, disease and war, it has been generally assumed that the “natural tendency” for population to increase would continue.  But the latest evidence shows that this is no longer a safe assumption.

In fact, it has been unsafe for some time, but the population explosion in the developing world, especially Asia, has masked a trend towards declining birth rates.  The “reproduction rate” for human fertility – that is, the rate required to keep the population stable, all other things being equal – is 2.1.  In 1950 the global fertility rate was 5.0.  It is 2.5 today, and the latest UN projection is that it will be 1.9 by the end of this century.

The UN’s latest Population Projections, published in June of this year, suggest a median world population figure of 9.7 billion in 2050, and 10.9 billion in 2100.  In other words, they see population growth continuing through the century but slowing down.  Their lower projection is of a population of 9.4 billion in 2050, remaining the same in 2100 – in other words, in the second half of this century, we might see the end of global population growth.

The population is aging as well.  In 1950 the median age of the world’s population was 24.  Today it is 31.  By the end of the century, the UN projections suggest that it will be 42.

In their book, Empty Planet: The Shock of Global Population Decline, Darrell Bricker and John Ibbotson go much further.  They argue that the UN projections underestimate the factors that are driving population growth downwards.  They argue that the global population in 2100 will be no higher than it was in 2000 and may even be lower.  And the population will be older.  They argue that factors such as economic prosperity, female emancipation, and urbanisation are leading women to exercise their right to have fewer children, or not have children at all.

This tendency is most evident in developed economies.  Remember, the replacement rate for fertility is 2.1:

  • The EU’s average fertility rate is 1.6
  • The USA’s fertility rate is higher than Europe’s – 1.9. Bricker & Ibbotson argue that this, together with its relatively open immigration policy (at least for now), means that its population is projected to grow from 345 million today, to 450 million by the end of the century – this is consistent with the UN projections
  • Japan’s fertility rate is 1.4. More than 25% of the population are of pensionable age. Median age is 48. Bricker and Ibbotson argue that Japan’s population will fall from 125 million in 2000 to just 83 million in 2100
  • Other Asian “tigers” are following suit. South Korea, Singapore and Taiwan all have fertility rates around 1.2.  Bricker and Ibbotson say that in the middle of this century, South Korea is set to overtake Japan as the “oldest” population on earth
  • China’s population is set to peak in 2030 at 1.4 billion, but the average age will then increase rapidly, and the population is projected by the UN to decline to just over 1 billion in 2100 – Bricker & Ibbotson believe it will fall further – back below 1 billion
  • India’s population is projected to continue to increase to 1.7 billion in 2060, and then begin to decline

The only region that will buck the trend will be Africa, which is set to grow from 800 million in 2000 to 2.5 billion by 2050, and projected to grow to 4.3 billion by 2100 (according to UN projections).  60% of its population is aged under 25.  Increasingly Africa will be anomalous: it will be the “Young Continent” – as we have previously discussed in our Africa blogs.

There is no fundamental disagreement between the UN and Bricker & Ibbotson as to the drivers of population change.  It is a matter of degree.  Bricker & Ibbotson see the downward drivers as stronger than the UN does, and largely irreversible.  The UN allows the possibility that countries that seek to do so will be able to raise their fertility rates.  Bricker and Ibbotson argue that such initiatives tend to have short-lived success, and that long-term downward trends will then reassert themselves.

But the direction of travel remains the same – only the duration of the journey is at issue.  Interestingly, the UN’s 2019 projections are slightly but significantly lower than the previous set, published in 2017.  The trend raises some big questions – both intellectual ones for futurists, and practical ones for business strategists and economists.

  • What does the projected decline and aging of China’s population do to the assumption that this will be the “Chinese century”? Will China enter the economic doldrums, as Japan has already done?
  • Will Africa’s population growth and the youth of its population make it a rising economic power, or will it fall foul of those Malthusian “checks” of hunger, disease and war?
  • Will Africa’s young people be welcomed by the rest of the world as a valuable resource, or seen as a mass-migration “problem”?
  • Will the USA, and other countries or regions with open migration policies fare better than those with greater reluctance to accommodate cultural differences?
  • Will countries with older populations be less inclined to spend, and more inclined to save for old age?
  • Will countries with older populations be less inclined to fight wars, or will they simply fight by other means – drones and cyber warfare, for example?
  • Will countries with older populations be less innovative and adaptable?
  • Will falling population mean we have a greener planet?
  • How will Governments balance the needs of older people with the expectations of people of working age?
  • How will technology allow new opportunities to address these problems?
  • Will countries seek to persuade (or coerce) women into having more babies? Will they succeed?

These 11 questions are a starter.  Increasingly we can expect to see the demographic time-bomb baked into foresight frameworks and scenario planning exercises.  And I am sure SAMI will have plenty to say about this.

If he could, what would Malthus be blogging?

Written by David Lye, SAMI Fellow and Director

The views expressed are those of the author and not necessarily of SAMI Consulting.

SAMI Consulting was founded in 1989 by Shell and St Andrews University. They have undertaken scenario planning projects for a wide range of UK and international organisations. Their core skill is providing the link between futures research and strategy.

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