Blog post

Demographic Tectonics

Publishing date
02 June 2011

What’s at stake

The previous issue of the blogs review emphasized the immediate migration challenge following the Arab Spring. This issue looks at longer-term migration challenges posed by a reshaping of the planet’s demographic map. In a recent report, the United Nations Population Division has revised upward its demographic projections. The new calculations, based on improved methods and the most recent demographic trends, essentially add a billion people to the population projection for 2100, and about 150 million to the projection for 2050. Among the factors behind the upward revisions is that fertility is not declining as rapidly as expected in some poor countries, and has shown a slight increase in many wealthier countries. According to the UN experts, much of the projected rise will occur in a group of high-fertility countries—defined as those where the average woman has more than 1.5 daughters.

Justin Gillis and Celia Dugger outlines the importance of the UN demographic revision in the NYT Green blog: expect a flurry of updates in coming months on projections for climate change, land use, water availability and many other issues as the consequences of these revisions work their way through the world of scientific prognostication.

Long-term migration forces

Pierre Buhler argues in the New-York Times that it is about time for Europeans to address the urgent need for sound management of the inescapable migratory flows from south to north. The latest United Nations population figures provide a dramatic glimpse of how the demographic map of the planet might be reshaped. One consequence of the growth curve is the pressure to emigrate generated by the annual arrival on the African labor markets of some 20 million youths. That bulge is liable to increase year after year, reaching 40 million by 2050.The migratory pressure will be directed in the first place toward Europe, whose population, in sharp contrast with Africa’s, is bound to age and stagnate.The United States and some other countries have long turned immigration into a public policy that, despite some stumbling blocks, has helped preserve a balanced age pyramid. In Europe, recent developments have shown the extent to which immigration can corrode the European construction.

Assaf Razin points in VoxEU that although price wedges for commodities and financial assets rarely exceed the ratio 2:1, wages of similarly qualified individuals in advanced and low-income countries differ by a factor of 10.

Shahram Khosravi
argues in FiveBooks that we have an average of two persons a day who die on the way to Europe. The rate is almost the same between Mexico and the United States. We have an increasing number of stateless people and an increasing number of undocumented migrants. Khosravi also points to the feminization of migration as an important new trend. Last year for the first time 50% of all migrants in the world were women (the figure for Europe is 51%). What is important in relation to the gender aspect is that usually they leave their own family. They leave their own kids to come to Rome or Los Angeles or Dubai to cook for other people's kids, to take care of other people's kids. This migration pattern corresponds to the new needs of advanced economies: we don't need a cheap labour force for factories anymore. We are not in the Europe of the 1960s. We need people who can cook for us, clean for us, and take care of our kids.

Revisiting a two-century long debate: how far can the population curve be bent?

The UN report upward revision for world population has revived a two-century-long debate about the risks and benefits of demographic growth and its interaction with innovation, nutrition and the environment. In the 1960s and 1970s the population growth rates — then of the same magnitude as those of sub-Saharan Africa today — fostered a number of controversies in the West about the capacity of the earth to feed a constantly growing mankind. John Bongaarts gives the history of thought background on whether more population is good or bad. The pessimistic “neo-Malthusian” view of which Paul Ehrlich, author of the “Population Bomb” in 1968, is a leading figure, posits that humanity is doomed due to overpopulation and overconsumption. Conversely the optimistic view, of which Esther Boserup was one of the earliest proponents, considers that technological innovation spurred by population growth will help meet the needs of growing populations. The line of reasoning is that necessity is the mother of invention.

Justin Gillis and Celia Dugger argue that even before the new estimates were issued, it was not at all clear that global agriculture could keep up with demand, which is rising both because of population growth and income growth. Even if food production does keep up, many experts worry that the environmental damage from agriculture, already substantial, will grow worse; it is already one of the biggest contributors to the greenhouse gases that are causing global warming. On top of that, an extra billion people will demand energy, much of which may need to come from burning fossil fuels, thus adding to the greenhouse problem.

David Lam
argued – in his presidential address at the annual meeting of the Population Association of America this year – that the challenges we are facing are staggering but really nothing compared to the challenges we faced in the 1960s. In spite of 50 years of the fastest population growth on record, the world did remarkably well in producing enough food and reducing poverty. Joseph Chamie expressed his confidence in the ability of technology to respond to the challenge of less-polluting energy production for a larger population.

Gary Becker and Richard Posner, while recognizing the pressure exerted by population growth on the environment and natural resources, believe that a 10.1 billion strong human population would be a good thing thanks to greater specialization, innovation, the greater supply of geniuses.

Uncertainties: technological progress and fertility levels

Back in 1981, Nathan Keyfitz pointed out the limits of population forecasting concluding that “relatively short-term forecasts, say up to ten or 20 years, do tell us something, but that beyond a quarter-century or so we simply do not know what the population will be.”In particular, past population forecasts have been often off-mark.

Joseph Chamie argues that if the future size of the world’s population was known, living conditions will hinge greatly on technology and lifestyle choices, which are hard to predict. These views echo that put forth in a 1996 article “Population Growth and Earth’s Human Carrying capacity” by Joel E. Cohen who noted that the globe’s capacity to support a larger human population was dynamic and uncertain, determined both by natural constraints and human choices.

The UN report underlines that its projections are highly sensitive to assumptions made about fertility levels in various parts of the world, emphasizing that small deviations can produce large differences over time. Fertility levels and growth rates have been traditionally hard to predict, as evidenced by the failure of all experts to anticipate the post World War II baby boom for instance. But as Ansley Coale established in a 1957 seminal contribution, there are key ingredients for population forecasting as fertility levels primarily determine the structure and rate of growth of a population.

Beyond *the* number

Andrew Revkin argues in his NYT blog that “the overall number, whatever you choose, could be a red herring”, arguing that emerging demographic challenges are best described as “a dangerous scattering of clusters bombs” rather than the “global scale, catastrophic “population bomb” concept that caught on in the 1960s”.

David Bloom stresses how different regions face different challenges, highlighting the “daunting challenge” facing Africa, by far the fastest growing continent currently and in the foreseeable future. Specific demographic challenges and opportunities at the global level that affect different parts of the world in different ways include imbalances in sex ratios, changes in age structure that may result in rapid aging, fast-growing working-age populations (also known as the “demographic dividend” phenomenon), international migrations flows, etc. Addressing these various challenges requires specific policies aimed at generating jobs, fostering knowledge, and increasing accountability, among other objectives.

Bruegel Economic Blogs Review is an information service that surveys external blogs. It does not survey Bruegel’s own publications, nor does it include comments by Bruegel authors.

About the authors

  • Jérémie Cohen-Setton

    Jérémie Cohen-Setton is a Research Fellow at the Peterson Institute for International Economics. Jérémie received his PhD in Economics from U.C. Berkeley and worked previously with Goldman Sachs Global Economic Research, HM Treasury, and Bruegel. At Bruegel, he was Research Assistant to Director Jean Pisani-Ferry and President Mario Monti. He also shaped and developed the Bruegel Economic Blogs Review.

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