Reading 2.1–2.2

Chapter 2: Population and Health

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Opening story: Shanghai pp. 1–3

The author has visited Shanghai many times over the years and watched it rebuild itself. Thousands of small houses were torn down and replaced by thousands of apartment towers, each at least a dozen stories high. From the observation deck of the new 128-story Shanghai Tower, on a day that was sunny, the city below was still hard to see: it was buried in air pollution.

• China has 1.4 billion people, and huge numbers are moving into cities.
• China has more than 100 cities with over 1 million people each.
• Shanghai is the biggest, at an estimated 22 million.

This rapid urbanization came from economic growth and population growth happening at the same time, and it has hurt both the environment and people's health. China's main fuel is coal. Burning it releases PM-2.5, a fine-particle pollutant. Bigger particles mostly irritate your eyes and throat, but PM-2.5 is small enough to damage the lungs and even pass into the bloodstream.

One study found that people in northern China, where air pollution is worse, live 5.5 fewer years on average than people in the south.

China's responses to the pollution:

• limited how much coal can be burned
• banned imports of plastics that were being brought in to be burned
• limited the number of cars allowed on the roads in major cities

The point of the story: the chapter looks at population trends at different scales and ties population growth to health, because the two are closely linked, in China and everywhere else.

2.1 Describe the Patterns of Population Distribution pp. 3–12

Geographers want to know two things about population: why some places are more crowded than others, and why populations grow at different speeds in different places.

• Demography is the study of overall population trends.
• Population geographers team up with demographers to figure out how and why those trends differ from place to place.

Scale matters a lot here (Chapter 1). A pattern you can see at a small scale, like one city or state, can disappear when you zoom out to a country, a region or the whole world. Example: people in one city might be moving from downtown out to the suburbs, but you'd never see that trend on a global map.

Population density pp. 4–5

Population density compares how many people live in a place with how much land it has. It pretends everyone is spread out evenly over that land.

Example, the United States: the book lists its territory as 5,692,815 sq miles (9,161,966 sq km), with 326 million people. That works out to an average of just over 86 people per sq mile (33 per sq km). This simple "people ÷ total land" number is called the arithmetic population density. It's useful for rough comparisons, like showing how much more crowded these countries are than the U.S.:

The catch: no country's people are actually spread out evenly. The U.S. average hides how empty much of Alaska is and how thinly populated large parts of the West are. So arithmetic density can badly mislead you.

Egypt is the classic example. With 97.6 million people, its arithmetic density is a modest-looking 252 per sq mile (97 per sq km). But most of Egypt's 384,345 sq miles (995,450 sq km) is desert. People are packed into the valley and delta of the Nile River: nearly 98% of Egyptians live on just 3% of the land. For Egypt, the arithmetic figure tells you almost nothing (Figures 2.3A and B).

Physiologic population density p. 6

Physiologic population density fixes the Egypt problem. It still counts people per square mile (or km), but it only counts arable (farmable) land in the area.

Back to Egypt: 252 per sq mile using all land, but 6,995 people per sq mile (2,701 per sq km) counting only farmland. That much higher number shows the real population pressure on Egypt's land. And it keeps climbing, even though Egypt keeps trying to expand its irrigated farmland.

Appendix B of the textbook lists both densities for every country, and comparing them tells you a lot:

• Switzerland (mountainous): its physiologic density is 10 times its arithmetic density, because only 1 acre in 10 is arable.
• Ukraine: 44,800,000 people; arithmetic density 192 per sq mile (74 per sq km); physiologic density 281 per sq mile (109 per sq km) thanks to its huge farmlands. Physiologic is 1.46 times arithmetic, because 1 of every 1.46 acres in Ukraine is arable.
• The gap between a country's two densities tells you what share of its land is farmable.
• Middle America and the Caribbean have high physiologic densities; South America's are moderate.
• India has the lowest physiologic density in South Asia, despite its enormous population.
• China and India both have well over 1 billion people, but physiologic density shows India has much more farmland per person than China.

Population distribution pp. 6–7

People aren't spread evenly across the world, or even within a single region or country. One-third of all humans live in China and India, yet both countries have huge areas with very few people: the Himalayas in India and a vast desert interior in China.

Besides density, geographers study population distribution: a description of the pattern people make across space. That includes where they're clustered (lots of people close together) and where they're dispersed (few people, spread out).

For most of history, people lived where they could grow food, so arable land and population density went hand in hand. Cities usually started in farming areas, and people lived nearest the most productive land. Recently, better farming technology and easier shipping of food have loosened that link. Maps now show people crowding into cities while spreading out more thinly in the countryside.

To map distribution, geographers use dot maps, where each dot stands for a set number of people. Up close (local scale), one dot might show a single farm in an empty rural area. At the global scale, the picture gets much more generalized (Fig. 2.4).

On a world dot map where each dot is 100,000 people, three giant clusters jump out. From largest to smallest they are East Asia, South Asia and Europe. North America comes fourth.

East Asia p. 8

Figure 2.5 is a dasymetric map. Instead of spreading people evenly, it uses landscape, land cover and topography to estimate where people actually cluster and where they're sparse.

• East Asia is the largest cluster: mostly China, plus Korea and Japan.
• Almost one-quarter of the world's people live here, 1.4 billion in China alone.
• Besides China's big cities, long "ribbons" of dense population stretch inland along the Huang He and Yangtze river valleys.
• Farmers in those valleys grow wheat and rice, enough to feed themselves and cities like Shanghai and Beijing.

South Asia p. 9

• The second-largest cluster, 1.5 billion people. India is its core, and it extends into Pakistan, Bangladesh and Sri Lanka.
• On a map it looks more tightly packed than East Asia because it's hemmed in by physical barriers where population drops off sharply:
  • the Himalayas to the north
  • mountain ranges in Afghanistan and Pakistan to the west
  • the Indian Ocean to the south and east
• As in East Asia, people concentrate in big cities, along coasts and in major river basins: the Ganges, Indus and Brahmaputra.
• It's growing faster than East Asia: India's growth rate is 1.17 vs. China's 0.56.
• Demographers predicted India would be the world's most populous country by 2030, with 1 of every 6 people on Earth living there.

Even the countryside is crowded. Bangladesh squeezes over 156 million people, nearly all small farmers, into an area about the size of Iowa. Across much of rural Bangladesh there are 3,000 to 5,000 people per sq mile. Iowa, in 2017, had only about 3.15 million people, with a rural density of 55 per sq mile.

Europe pp. 9–10

• Over 725 million people, which is less than half the South Asia cluster.
• Terrain and environment don't predict where Europeans live as well as they do in Asia. In Asia, dense population traces coastlines and rivers more obviously. Europe is crowded even in rough, mountainous areas.
• Europe was where the Industrial Revolution and the second urban revolution began, so it industrialized and urbanized before Asia did.
• Its cities grew during the 1800s and 1900s, especially in industrial zones: northern France, western Germany, northern Italy, and east into Russia.
• Share of people living in urban places: Germany 77%, United Kingdom 83%, France 80%.
• With so many people in cities, Europe's countryside is emptier than rural East and South Asia.

Put together, East Asia, South Asia and Europe hold about 4 billion of the world's 7.7 billion people. No other place on Earth has a cluster even half the size of any of these three. In fact, South America and Africa combined barely have more people than India alone.

North America pp. 10–11

The fourth-largest cluster, included mainly as a reference point for readers in the U.S. and Canada. Its densest zone runs along the urban East Coast and into Canada:

• U.S.: from Boston in the north down to Washington, D.C.
• Canada: from Quebec City through Montreal, Ottawa, Toronto and Windsor

Dense settlement runs from one city straight into the next. Urban geographers call a giant continuous urban region like this a megalopolis.

• The cities of this megalopolis hold more than 70 million people.
• Half of Canada's population lives in the Quebec City–Windsor corridor.
• About 20% of Americans live in the Boston–Washington, D.C. corridor.
• The combined megalopolises of the northeastern U.S. and southeastern Canada make a cluster about one-quarter the size of Europe's.

If you've been stuck in traffic there, it feels dense, but compared with East Asia this megalopolis is small. Even New York City's density doesn't come close to the biggest cities in South Asia:

Reliability of population data pp. 11–12

The U.S. runs a census every 10 years, and before each one the government advertises to get every person counted. Much federal funding is handed out based on population, so states and cities want every resident counted. An undercount means less money for city governments.

Who gets missed? Research shows these groups are less likely to fill out a census form:

• migrants
• racial minorities
• families who double up in rentals or have no home
• low-income families

Advocates for these groups push people to return their forms. Their worry: groups that are already disadvantaged lose out even more when an undercount cuts funding for services. An undercount also means less political representation, because each state's number of seats in Congress is based on the census count.

Two recent controversies:

• Sampling vs. counting. Advocacy groups have pushed the Census Bureau to sample the population and calculate the totals statistically, arguing it would be more accurate. The Bureau has stuck with its traditional method: trying to count every single person within U.S. borders.
• The citizenship question. Supporters say the census should distinguish citizens from unauthorized (undocumented) immigrants. Opponents say the question would scare off anyone with legal worries about citizenship, producing an inaccurate count.

These debates, plus the cost of counting everyone, make accurate counts hard. Several organizations still collect population data by country:

• the United Nations, which gathers and publishes official statistics from national governments
• the World Bank
• the Population Reference Bureau

Compare their numbers and you'll find they don't always match. Figures for population, growth rates, food supply, health and income are often informed estimates, not actual counts.

Section 2.1 in a nutshell p. 54

• Two ways to measure density: arithmetic (people per unit of all land) and physiologic (people per unit of arable land).
• Distribution is very uneven. The densest places are where growing and harvesting food is easiest. The biggest concentrations are in the most productive farming regions of East Asia, South Asia, Europe and North America.

Quiz checklist for the intro and 2.1

Tick off what you know. Your ticks are saved in this browser only.

• Shanghai: 128-story tower (over 2,000 ft / 600 m); smog; ~22 million people; China 1.4 billion, 100+ cities over 1 million
• Coal → PM-2.5 (fine particles: lungs and bloodstream); north China lives 5.5 years less
• China's fixes: limit coal, ban imported plastics for burning, limit cars
• Demography definition; population geographers work with demographers
• Scale: local trends (downtown → suburbs) can vanish at the global scale
• Yangon field note: density + poverty + weak infrastructure = vulnerability; 2008 cyclone, Irrawaddy delta, ~100,000 dead
• Population density definition (assumes even spread)
• Arithmetic density; U.S. 86/sq mi (33/sq km), 326 million people
• Bangladesh 2,962 · Netherlands 1,068 · Japan 869 (per sq mi)
• Arithmetic density misleads: Alaska, the West, Egypt
• Egypt: 97.6 million; 252/sq mi; 384,345 sq mi mostly desert; 98% on 3% of land (Nile valley and delta)
• Luxor field note: physical environment shapes where people live, not just culture
• Physiologic density definition (people per arable land); Egypt 6,995/sq mi (2,701/sq km)
• Switzerland physiologic = 10× arithmetic (1 in 10 acres arable)
• Ukraine: 44.8 million; 192 vs. 281/sq mi; ratio 1.46
• The gap between the two densities = share of land that's arable
• Middle America/Caribbean high physiologic; South America moderate; India lowest in South Asia; India has more arable land per person than China
• 1/3 of humanity in China + India; empty Himalayas and Chinese desert
• Population distribution definition; clustered vs. dispersed
• Historically people lived near food; technology and transport are changing that
• Dot maps (Fig. 2.4: 1 dot = 100,000 people); dasymetric maps (Fig. 2.5)
• Cluster rank: East Asia, South Asia, Europe, North America
• East Asia: ~¼ of world, 1.4 billion in China; Huang He and Yangtze ribbons; wheat and rice
• South Asia: 1.5 billion; India, Pakistan, Bangladesh, Sri Lanka; barriers (Himalayas, Afghan/Pakistani mountains, Indian Ocean); Ganges, Indus, Brahmaputra
• India growth 1.17 vs. China 0.56; India most populous by 2030 (1 in 6 people)
• Bangladesh: 156+ million in an Iowa-sized area; rural 3,000–5,000/sq mi vs. Iowa 55 (3.15 million, 2017)
• Europe: 725+ million; dense even in mountains; Industrial Revolution and second urban revolution; N. France, W. Germany, N. Italy, Russia; urban share: Germany 77%, UK 83%, France 80%
• Big three ≈ 4 billion of 7.7 billion; South America + Africa ≈ India
• Megalopolis: Boston–Washington, D.C. and Quebec City–Windsor; 70+ million; half of Canada; 20% of Americans; ¼ of Europe's cluster
• NYC 28,717 vs. Mumbai 68,400 vs. Dhaka 122,700 (per sq mi)
• Census every 10 years; money and congressional seats; who gets undercounted
• Sampling debate; citizenship question debate
• UN, World Bank, Population Reference Bureau; data are often informed estimates

2.2 Identify and Explain Influences on Population Growth over Time pp. 12–33

Worry about "too many people" is not new. In the late 1960s, Paul Ehrlich's book The Population Bomb set off alarms worldwide by arguing that population was growing faster than food production. But that fear goes back much further, to an essay a British economist published in 1798.

Malthus pp. 12–13

Thomas Malthus published An Essay on the Principles of Population in 1798. His warning: population was outrunning the food supply needed to keep people alive. His reasoning rested on two kinds of growth:

• Food grows linearly: a little more farmland and a few more crops are added each year.
• Population grows exponentially: each year's growth builds on the year before, like compound interest. (See the world population chart under Doubling time for the real numbers.)

He kept revising the essay from 1803 to 1826 and fought back hard against critics. His predictions assumed that what a country eats depends on what that country grows.

Why Malthus was wrong (so far):

• Countries aren't closed systems. He didn't foresee globalization: farm products being traded all over the world.
• Mercantilism, colonialism and capitalism connected the Americas, Europe, Africa, Asia and the Pacific. Along the way, farming methods spread, and crops and livestock crossed oceans to new places whose climates and soils suited them.
• Example: the potato is tied to Ireland's identity, but Irish farmers only started growing it in the 1700s, after it arrived from South America.
• Countries with little arable land could import all kinds of crops. Only 2% of Norway's land is arable, but it imports most of its food, getting around its limits on growing food.
• Food production has also exploded in recent decades. More land has been cultivated, and better seeds, pesticides, fertilizers, irrigation and constant innovation have raised yields per acre enormously. In the 2000s, bioengineering keeps adding new hybrids, genetically modified organisms (GMOs) and new fertilizers.

But the debate isn't over. Modern farming has environmental costs, which raises real doubts about whether agriculture can keep expanding forever. Neo-Malthusians have revived Malthus's ideas, but they focus far more on population growth than on food:

• Many demographers expect world population to level off later this century.
• Neo-Malthusians argue overpopulation is still a real problem that will cause human suffering.
• They doubt Earth can support many more people, and expect growth to be stopped when we hit the limits of resources: not just food, but also energy and water.

Natural increase rate pp. 13–16

Geographers and demographers measure how populations change and what they're made of, so they can compare countries, study the effects of population change and make predictions. The natural increase rate is built from two statistics:

• Crude birth rate (CBR): live births per year for every 1,000 people (Fig. 2.7).
• Crude death rate (CDR): deaths per year for every 1,000 people (Fig. 2.8).
• Natural increase = CBR − CDR. It shows how a population changes on its own, leaving out migration: people moving in (immigration) and out (emigration) aren't counted.
• Europe and Russia have negative natural increase: without immigration, their populations would be shrinking.

Growth rates rise and fall over time and across regions:

• The Soviet Union grew fast in the mid-1900s, but growth dropped sharply after it broke up in 1991.
• About 30 years before the book, India grew at almost 3% a year, faster than most African countries. Then India fell below Africa. Now Africa's natural increase is well above India's (2.43% vs. 1.17%). Parts of sub-Saharan Africa are still affected by HIV/AIDS, which killed millions, left children orphaned, cut life expectancy and held down growth.
• Muslim countries in North Africa and Southwest Asia still grow fast: Sudan 2.55%, Yemen 2.52%, Afghanistan 2.65% and the Palestinian territories 2.83%. For much of the late 1900s, growth in this region rose while most of the world's fell. More recently, some fast growers, such as Iran, Oman and Morocco, have dropped sharply.
• The big pattern demographers point to: where custom limits women's education and careers and men run family life, natural increase tends to be high.

Asia:

• South Asia matters a lot for world growth because it includes India. India's growth has slowed a lot, even dipping slightly below the world average, but it's still higher than China's.
• East Asia, the most populous region, is different: China's official natural growth is well below the world average, and Japan's population is shrinking.
• Southeast Asia grows faster, but has far fewer people than East or South Asia. Key countries like Indonesia and Vietnam are slowing, and Thailand's growth is negative.

South America:

• Growth was high a generation ago but has dropped a lot. The region as a whole still grows a little over 1%.
• Brazil fell from 2.9% in the mid-1960s to 0.8%.
• Argentina, Chile and Uruguay grow well below the world average.

The slowest growers:

• The lowest (including negative) growth rates are in the global economic core: the U.S. and Canada, across Europe, to Japan. Australia and Uruguay are in this group too.
• But wealth isn't the only cause. After the Soviet Union broke up in 1991, Russia and several other former Soviet countries shrank because of worsening health, high rates of alcoholism and drug use, more male suicides, and economic trouble.
• Russia's economy has since improved, but its birth rate is still low. The same goes for Ukraine (also formerly Soviet), which has negative growth.

The big picture:

• World population went from 1.6 billion in 1900 to 6.1 billion in 2000, and passed 7.7 billion in 2019.
• Growth doesn't just come from more babies. It also comes from people living longer. World life expectancy was 30 years in 1900 and 72 in 2016.
• Demographers expect world population to level off at 10 to 11 billion sometime between 2050 and 2100.
• Because birth rates are falling and lifespans are rising, the mix of young vs. old people in 2050 will look very different from 1900.

India pp. 17–20

A world map of growth rates is a useful overview, but it hides differences inside countries. India is a federation of 29 states and 7 union territories (book figures), and those states differ a lot culturally and politically.

• Northern states grow far faster than the national average (Fig. 2.9).
• Southern and western states grow much more slowly.
• Women in the south and west have:
  • higher literacy rates (Fig. 2.10)
  • more land ownership
  • better access to health care
  • more access to birth control
  Together, these keep growth lower in the south and west than in the north and east.

India's population policies, in order:

1. 1952: India became the first country in the world with a population planning program, aiming to lower fertility and slow growth.
2. 1976: the government ran a mass sterilization drive, focused on forcibly sterilizing men with three or more children.
   • Overeager officials, some with quotas to meet, brought in men who had no children at all.
   • One doctor said he quietly let childless men out the clinic's back door without operating.
   • The state of Maharashtra sterilized 3.7 million men and women before public anger turned into riots and the program was dropped (Fig. 2.11).
   • Other states also forced sterilizations, at a heavy social and political cost.
   • In total, the 1976 program sterilized 6 million men.
3. After the protests: forced sterilization ended. The national government now just sets goals for lower birth rates, and each state can make its own policy. Example: Maharashtra pays newly married couples cash if they wait two years after marriage before their first child.
4. Today: the focus moved from sterilizing men to giving women birth control.
   • Injectable contraceptives are available to women nationwide.
   • Most states use advertising and persuasion, and posters urging small families are everywhere.
   • The government funds family planning clinics even in the most remote villages.

More and more women, especially in southern and western India, use modern contraceptives. The contraceptive prevalence rate is the percentage of women ages 15–49 who are using at least one birth control method, or whose partner is.

The lesson of India: a world map is just an introduction. What you see at the global scale doesn't tell the full story of what's happening inside each country or region.

Doubling time pp. 21–22

Doubling time is how long a population takes to double at its current growth rate. Every growth rate has one.

Money example: invest $100 at 10% a year, compounded, and it becomes $200 in about 7 years, $400 after about 14, and $800 after about 21. So a 10% growth rate means a doubling time of roughly 7 years.

How fast world population doubled:

• 2,000 years ago: about 250 million people.
• 1650: 500 million. That first doubling took more than 16 centuries.
• 1820 (Malthus was still writing): 1 billion, only 170 years later (Fig. 2.13).
• 1930: 2 billion, just over a century later. The doubling time had dropped to about 100 years and was still falling fast.
• 1975: 4 billion, only 45 years later. The population explosion was at full speed.
• Mid-1980s: doubling time hit its low of just 39 years.
• Since then: policies to slow growth, including China's one-child policy, stretched it back out to 54 years.

• For today's demographers, doubling time matters less and less. With populations falling in many places, fears of a rapid global doubling are fading. Signs like the lengthening doubling time suggest the 1900s' explosive growth will give way to a slowdown this century.
• No single factor explains the growth differences on the map. Both prosperity and social upheaval can cut natural growth.
• Economic well-being brings urbanization, more education, later marriage and family planning, and all of these lower growth.
• In general, the more urbanized a population, the lower its natural increase. You can check this by comparing natural increase with percent urban in the textbook's Appendix B.

Total fertility rates pp. 22–25

Demographers who expect world growth to slow down and stabilize base that on two things: people living longer, and lower total fertility rates.

• The total fertility rate (TFR) is the average number of children born to women of childbearing age (15 to 49). It tells you whether births can replace deaths.
• A country needs a TFR of 2.1 to replace itself and stay stable without immigration.
• More than 95 countries, home to 41% of the world's people, have dropped below replacement level (Fig. 2.14).

• UN prediction: the world's combined TFR will drop below 2.2 by 2050.
• The world figure blends low-TFR regions like Europe with high-TFR regions like Africa. In 2016 the world TFR was 2.4, ranging from 1.2 in South Korea to 7.2 in Niger.

Forecasting is hard because it depends so much on choices made by women of childbearing age. In richer countries, more women stay in school longer, build careers and marry later, so they have children later. That makes the population older, which raises the old-age dependency ratio: the number of people over 65 compared with the working-age population (ages 15–64).

• Europe: 29.9 old-age dependents per 100 working-age people, expected to hit 47 by 2050.
• Sub-Saharan Africa: only 5.7.
• Africa's challenge is the opposite: a high child dependency ratio (74, vs. just 23 in Europe).

Why aging is a problem:

• Older people retire and eventually have health problems, so they need pensions and medical care.
• Younger workers pay the taxes that fund those services.
• As the share of older people grows, the share of younger people shrinks.
• So aging countries have fewer young taxpayers supporting more and more retirees.

An aging country has two ways to get more taxpayers: raise its TFR, or allow immigration. Immigrants tend to be young workers who pay taxes on their wages, homes and purchases.

What if a country resists immigration while aging? Japan is the case study.

• Japan's population has stopped growing and is projected to keep shrinking.
• It fell from a peak of 128.06 million in 2008 to 126.8 million in 2017.
• Japan expects about 100 million by 2050, a loss of 20%.
• Japan was closed to outsiders for centuries, and its government still discourages immigration. Over 98% of its people are ethnically Japanese, per government statistics.

TFRs are now falling almost everywhere, mostly because of family planning.

• In some lower-income countries, government and nongovernmental (NGO) programs together encourage women to have fewer children.
• Some women also choose fewer children because of economic and social uncertainty.

Some drops have been dramatic:

• Kenya: down to 3.85 in 2016.
• China: fell from 6.1 to 1.75 in just 35 years, dropped to 1.5 in 2010, then was 1.62 in 2016.
• Iran: once the government allowed family planning, TFR fell from 6.8 in 1980 to 1.7 in 2016.

Demographers once assumed every government would want a low TFR. Many governments now have second thoughts, because an economy needs a young, energetic working-age population to work, pay taxes and support older people over the long run.

Some governments are fighting back against falling birth rates:

• Sweden, Russia and other European countries offer financial incentives like long maternity leave and state-paid daycare to prospective mothers.
• Japan runs public service campaigns urging men to do more housework.
• These programs and debates have had only limited success at producing lasting population growth.

So why is world population still rising if so many countries have low TFRs or are shrinking? The world TFR was 2.43 in 2016, still above the 2.1 replacement level. Ehrlich's "population bomb" isn't ticking as fast, but growth continues. Low-growth countries are partly offset by countries still adding lots of people: India, Indonesia, Bangladesh, Pakistan and Nigeria.

Population pyramids pp. 25–28

Geographers care about more than distribution and growth. They also study population composition: the makeup of a population by age, sex and other traits like marital status and education. Age and sex are the most important, and they're shown with population pyramids, graphs of a population's age and sex structure (Fig. 2.15).

How to read one:

1. Along the bottom (horizontal) axis: males on the left, females on the right.
2. Up the side (vertical) axis: age groups, usually 5-year steps.
3. The youngest group (starting at age 0) is at the bottom; the oldest is at the top.
4. Every pyramid starts at 0, but they don't all end at the same age. Countries with longer life expectancies have more people in the top bracket, so always check the top bracket.

Lower-income countries (high birth rates and high death rates):

• The pyramid looks like a real pyramid or an evergreen tree: wide at the bottom, narrow at the top.
• The youngest groups are the biggest share of the population.
• In most lower-income countries, the three groups up to age 14 make up more than 40% of everyone.
• From ages 15–19 upward, each group is smaller than the one below it.
• The three oldest groups are under 10% of the total.
• Close variations on this shape: Pakistan, Yemen, Guatemala, Cameroon and Laos.

Higher-income countries:

• Their pyramids don't look like pyramids at all. Families are smaller and there are fewer children.
• The shape is more like a slightly lopsided chimney, with the biggest groups in the middle instead of at the bottom.
• That middle-age bulge keeps moving up as the population ages and TFR falls (Fig. 2.16).
• Wealthy, low-TFR countries like Italy, France and Sweden fit this model.

Religion and growth pp. 26–28

A population's religious makeup can affect its growth rate, and so the shape of its pyramid.

• The Roman Catholic Church doesn't support contraception.
• Some conservative branches of Islam also disapprove of contraceptives.
• Example: conservative Islam is practiced in northern Nigeria, and the north grows noticeably faster than the south.

But in many places, the main religion tells you little about population trends.

• Some of the world's slowest-growing areas are right in the heart of the Roman Catholic world, even though Catholic teaching opposes birth control and abortion (Fig. 2.17).
• Oddly, people seem to follow that teaching more closely the farther they live from the Vatican, the Church's headquarters.
• The Philippines, for example, has a fairly high growth rate.

Islam shows a different pattern:

• Saudi Arabia, home of Mecca (the hearth of Islam), grows fairly fast, about 2% a year.
• Indonesia, thousands of miles from Mecca, launched a nationwide family planning program in 1970, when its growth was high.
• Conservative Muslim leaders objected, but the government kept the program going using a mix of coercion and inducement.
• Growth fell to 1.6% by 2000 and 1.1% by 2016.

The demographic transition pp. 28–31

The demographic transition is a model saying that a country's birth and death rates change in predictable ways as it develops economically (Fig. 2.18). It's based on what happened to population in western Europe after the Industrial Revolution.

Stage 1: Low growth p. 29

• World population rose from 250 million 2,000 years ago to 500 million in 1650. Graphs often draw this as a smooth, gentle upward slope.
• In reality, population went up and down as birth and death rates swung with disease, crop failures and war.
• Stage 1 is the starting phase, where every place spent most of human history.
• It's unpredictable: high birth rates and equally high death rates.
• Epidemics and plagues keep death rates high, sometimes higher than birth rates.

The Black Death (bubonic plague) of the 1300s pushed deaths above births in Great Britain and western Europe, hitting in waves:

• It started in Crimea, on the Black Sea.
• It spread along trade routes to Sicily and other Mediterranean islands.
• It moved north from the Mediterranean by contagious diffusion and on traveling rats, whose fleas actually spread the disease.
• After striking a region, it tended to come back within a few years in another wave.
• Estimates say it killed between one-quarter and one-half of the population.
• Death rates were highest in western Europe, where regions traded the most, and lowest in the east, where cooler climates and less connected populations slowed its spread.
• Cities and towns across Europe were devastated.
• Great Britain's population fell from nearly 4 million to just over 2 million.

Famine and war also held growth down:

• A famine in Europe just before the plague probably helped it spread by weakening people's immune systems.
• Famines in India and China in the 1700s and 1800s killed millions.
• At other times, destructive wars erased population gains.

Stage 2: High growth pp. 29–30

Stage 2: birth rates stay high, death rates drop fast, and natural increase is very high.

In Europe:

• Stage 2 began after the Industrial Revolution (around 1750).
• Better access to food, sanitation and health care sharply lowered death rates.
• Farming improvements that came before the Industrial Revolution made food supplies more stable.
• Sanitation made towns and cities safer from epidemics, soap came into wider use, and modern medicine started to catch on.

Church records from Great Britain, where the Industrial Revolution started, show the drop.

• Before 1750, European death rates may have averaged about 35 per 1,000, with birth rates under 40.
• By 1850, Britain's death rate was down to about 16 per 1,000.
• Death rates fell fast while birth rates stayed high, and Britain's population exploded.

Today:

• Stage 2 countries are much lower-income countries, with fairly high birth rates and natural increase and slowly falling death rates.
• Lower-income countries that went through stage 2, and ones in it now like Palestine and Afghanistan, got help from the spread of Western medicine, including childhood vaccinations.

Stage 3: Moderate growth p. 30

Stage 3: birth rates fall quickly, death rates keep falling, and natural increase slows down.

• Birth rates start dropping but stay above death rates, so the population still grows, just more slowly.
• In Great Britain, this was roughly 1870 through the two world wars of the 1900s.
• New opportunities, especially for women, often didn't fit with having large families.
• Women put off marriage and having children.
• Medical advances cut infant and child deaths, so families no longer felt they needed many children to make sure some survived.
• Young adults married later, which naturally lowered TFR and crude birth rates.
• Stage 3 starts when a country's birth rate begins to fall.
• Today: middle-income countries like Brazil. Brazil's birth rate fell because of wider access to modern contraceptives, not because people married later.
• Better education for women goes along with lower birth rates. Studies in Mali found girls who attend school end up with just over half as many children as women with no schooling. Expanding education for girls and women there will likely have a big effect on future growth.

Stage 4: Low growth pp. 30–31

Stage 4: low birth rates, low death rates, and natural increase that's stable or slowing.

• In Great Britain after 1950, both rates fell to low levels, so growth slowed or stopped.
• Better modern contraceptives and wider access to legal abortion after the 1950s helped keep birth rates very low in Britain and other higher-income countries.
• Today: higher-income countries like the United States and United Kingdom.
• Birth rates there are low because contraceptives spread, abortion became available, and many women decided to have fewer children, none at all, or children later in life.

Stage 5: Negative growth p. 31

Stage 5: very low birth rates, rising death rates, and falling natural increase. Examples: Japan and Russia.

• The world's growth rate is now about 1.2% (maybe a bit lower), yet world population still grows by more than 80 million people a year.
• Since women are having fewer children, many demographers predict that as more countries enter stage 5, the world will reach zero population growth within about 50 years.
• That would give Earth a stationary population level (SPL).

Population forecasts keep getting revised, and the expected dates for stabilizing keep moving later. In the late 1980s, the World Bank predicted:

• These turned out to be unrealistic.
• China passed 1.2 billion in 1994, and India reached 1 billion in 1998.
• Newer reports predict China will "stabilize" at 1.45 billion in 2030 and India at 1.7 billion in 2060.

Section 2.2 in a nutshell pp. 54–55

• Malthus warned in the late 1700s that Britain would face mass famine from rapid growth. It didn't happen, but fast world growth since then has won his ideas new followers. His argument works better at the global scale than for single places, since trade between places weakens the link between one place's population and its own food. Even globally, rising farm output complicates his logic.
• TFR (average children per woman) shows how fast populations grow. Below 2.1 means not growing. More and more countries, especially rich ones, aren't growing, which makes it harder for working-age people to support children and the elderly.
• Population pyramids show age and sex structure. They got the name because early on, most countries had the most children, then fewer young adults, older adults and elderly, forming a pyramid. Wealthier countries' pyramids today aren't pyramid-shaped, because their biggest groups are middle-aged.
• The demographic transition model explains the huge growth of recent centuries: death rates fall while birth rates stay high, and growth slows once birth rates fall too. Birth rates fell first in more urban, wealthy countries. They're falling nearly everywhere now, but remain fairly high in poorer, less urban places.
• Women's education and opportunities track closely with lower natural increase, and will be central to population trends in the coming decades.

Quiz checklist for 2.2

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• Ehrlich, The Population Bomb (late 1960s): population outpacing food
• Malthus, 1798 essay: food grows linearly, population exponentially; revisions 1803–1826; assumed countries eat only what they grow
• Why he was wrong: not closed systems; globalization; mercantilism, colonialism, capitalism; crops spread (potato: South America → Ireland in the 1700s); Norway 2% arable, imports food
• Higher yields: seeds, pesticides, fertilizers, irrigation, bioengineering and GMOs (Ch. 11)
• Neo-Malthusians: focus on population; limits of food, energy and water; environmental costs of farming
• CBR and CDR (per 1,000 per year); NIR = CBR − CDR; excludes migration; Europe and Russia negative
• Soviet growth fell after 1991; India ~3% 30 years ago, now Africa 2.43% vs. India 1.17%; HIV/AIDS
• Sudan 2.55, Yemen 2.52, Afghanistan 2.65, Palestinian territories 2.83; Iran, Oman and Morocco declining
• Limited opportunities for women and male-dominated families → high natural increase
• India slightly below world average but above China; China well below; Japan shrinking; SE Asia higher; Indonesia and Vietnam declining; Thailand negative
• South America a bit over 1%; Brazil 2.9% (mid-1960s) → 0.8%; Argentina, Chile, Uruguay below average
• Lowest growth in the global economic core (U.S., Canada, Europe, Japan, Australia, Uruguay)
• Russia after 1991: health, alcoholism, drugs, male suicide, economy; birth rate still low; Ukraine negative
• 1.6 billion (1900) → 6.1 billion (2000) → 7.7 billion (2019); life expectancy 30 → 72; level off at 10–11 billion (2050–2100)
• India: 29 states + 7 union territories; north grows fast; south and west slower (female literacy, land ownership, health care, birth control)
• 1952 first population program; 1976 forced sterilization (3+ children, quotas, Maharashtra 3.7 million, riots, 6 million men)
• After: states set own policies (Maharashtra pays couples to wait 2 years); shift to birth control for women, injectables, posters, village clinics
• Contraceptive prevalence rate definition; India 55.1%; Andhra Pradesh 69.8, Maharashtra 63.5, Bihar 26.0, Meghalaya 21.1
• Doubling time; $100 at 10% doubles in ~7 years
• 250 million (2,000 years ago) → 500 million (1650) → 1 billion (1820) → 2 billion (1930) → 4 billion (1975); doubling time 39 years (mid-1980s) → 54 years now
• Doubling time losing its punch; no single factor; more urbanized → lower natural increase
• TFR definition (women 15–49); replacement 2.1; 95+ countries, 41% of people below replacement
• UN: world TFR below 2.2 by 2050; 2016 world 2.4, South Korea 1.2, Niger 7.2
• Old-age dependency ratio (65+ vs. 15–64): Europe 29.9 → 47 by 2050; sub-Saharan Africa 5.7; child dependency Africa 74 vs. Europe 23
• Aging: pensions and medical care, fewer young taxpayers; fixes: raise TFR or immigration
• Japan: 128.06 million (2008) → 126.8 million (2017) → ~100 million by 2050 (−20%); discourages immigration; 98%+ Japanese
• TFR drops: Kenya 3.85 (2016); China 6.1 → 1.75 in 35 years, 1.5 (2010), 1.62 (2016); Iran 6.8 (1980) → 1.7 (2016)
• Governments now worry about low TFR; Sweden and Russia incentives; Japan housework campaigns; limited success
• World TFR 2.43 (2016) above replacement; growth from India, Indonesia, Bangladesh, Pakistan, Nigeria
• Population composition; how to read a pyramid (males left, 5-year groups, check the top bracket)
• Lower-income pyramid: 0–14 over 40%, top three groups under 10%; Pakistan, Yemen, Guatemala, Cameroon, Laos
• Higher-income "chimney": bulge in the middle moving up; Italy, France, Sweden
• Religion: Catholic Church and some conservative Islam oppose contraception; northern Nigeria grows faster; low growth in the Catholic heartland; the Philippines grows fast
• Bordeaux field note (de Blij, from Dakar): "Where are all the children?"
• Saudi Arabia 2%; Indonesia program 1970 (coercion + inducement) → 1.6% (2000) → 1.1% (2016)
• DTM definition; based on western Europe after the Industrial Revolution
• Stage 1: high and fluctuating rates; Black Death 1300s (Crimea → Sicily; rats and fleas; ¼–½ died; worst in the west; Britain ~4 million → ~2 million); famines; wars
• Stage 2: after ~1750; food, sanitation, soap, medicine; Britain death rate ~35 → ~16 by 1850; Palestine and Afghanistan today; vaccines
• Stage 3: Britain ~1870 through the world wars; women's opportunities, later marriage, lower infant deaths; Brazil (contraceptives); Mali (schooled girls ~half as many children)
• Stage 4: Britain after 1950; contraception and abortion; U.S. and UK today
• Stage 5: rising death rates; Japan and Russia; world ~1.2%, 80+ million a year; ZPG in ~50 years; SPL
• Late-1980s SPL predictions (U.S. 276 million/2035 etc.) proved wrong; China 1.2 billion (1994), India 1 billion (1998); new: China 1.45 billion (2030), India 1.7 billion (2060)