Mission 1: Why do more than 9 in 10 people in China live on one side of a single line?

Distribution and density

• Population distribution: how people are spread across an area.
• Population density = population ÷ area (people per km²).
• Distribution describes where; density describes how many per km².

An uneven world

• People are spread very unevenly. Asia alone holds about 59% of the world's people (2024).
• About 39% of people live within 100 km of a coast (2010).
• Hot and cold deserts, high mountains and dense rainforest are almost empty.

Physical factors

• Climate: warmth and reliable rainfall support farming; extreme heat, cold or drought repel settlement.
• Relief: flat lowlands are easy to farm and build on; steep, high land is not.
• Water: rivers, lakes and groundwater for drinking and irrigation.
• Soils: fertile river (alluvial) and volcanic soils support dense farming populations.
• Resources: minerals and energy can draw people even to harsh places.

Human factors

• Economic: jobs, industry, ports and trade routes.
• Political: capital cities, planned new towns, controls on migration.
• Historical: long-settled river valleys keep their people; cities grow where cities already are.
• Technology: irrigation, air conditioning and desalination let people live where physical conditions are harsh.

Scale and relative importance

• Patterns change with scale: a thinly populated country can contain some of the densest cities on Earth.
• At the global scale, physical factors set broad limits.
• Within those limits, human factors increasingly decide exactly where people live.
• Exam move: the guide asks for "the relative importance of different influences". Argue which factor matters most at which scale, and support it with a located example.

Example 1: China's Hu Line

• In 1935 the geographer Hu Huanyong drew a line from Aihui (now Heihe) in the north-east to Tengchong in the south-west.
• With 1933 data, 96% of China's people lived south-east of it.
• 2010 census: about 94% of people on about 43% of the land. 2020 census: 93.5%, using a prefecture-level version of the line.
• The split has barely changed in about 90 years.

Why the line holds

• South-east: monsoon rainfall, lowland plains and great river valleys (Yangtze, Pearl) with fertile soils.
• North-west: the Tibetan Plateau, deserts and steppe, which are high, cold or dry.
• The line roughly follows the 400 mm annual rainfall line, which separates the wetter, mainly farming lands of the east from the drier, mainly pastoral lands of the west.
• Human factors then reinforced the pattern: cities, industry and ports grew in the south-east, and migrants followed the jobs.

Example 2: Egypt

• About 95% of Egyptians live in the Nile Valley and Delta.
• Only about 5–6% of Egypt's land is used by its population; the rest is desert.
• One physical factor dominates: water. The Nile supplies water for farming and cities through a desert.
• The result is a narrow ribbon and delta of very dense settlement, with near-empty land on either side.

Mission 2: Is China a rich country or a poor one?

Classifying countries by income

• The World Bank groups countries by GNI per capita (Atlas method, US$).
• For July 2026 to June 2027 (2025 data):
  • Low income: $1,175 or less
  • Lower-middle income: $1,176–4,635
  • Upper-middle income: $4,636–14,375
  • High income: more than $14,375
• 218 economies: 25 low, 47 lower-middle, 59 upper-middle and 87 high income.
• Pattern: most low-income economies are in sub-Saharan Africa; high-income economies cluster in Europe, North America, the Gulf, East Asia and Oceania.

Middle income and emerging economies

• Middle-income countries span a huge range, from just above $1,175 to $14,375 per person.
• Emerging economies are middle-income countries with rapid growth, industrialisation and fast-rising trade, such as China, India and Brazil.
• Thresholds are updated every July. In 2026 Jordan, Micronesia, the Philippines, Sri Lanka and Viet Nam moved up to upper-middle income.

Beyond income: the HDI

• The Human Development Index combines three dimensions:
  • a long and healthy life (life expectancy at birth)
  • knowledge (expected and mean years of schooling)
  • a decent standard of living (GNI per capita, PPP $).
• Strength: broader than income alone.
• Limitations: a national average hides gaps between regions and groups, and it leaves out other things people value.

Core and periphery

• Within a country, development is often uneven. A core region concentrates capital, jobs, infrastructure and power; the periphery has less of each.
• Young workers, capital and raw materials flow from periphery to core. These backwash effects widen the gap (Myrdal's cumulative causation; Friedmann's core–periphery model).
• Later, growth may spread outwards (spread effects) as costs rise in the core.

China's core and periphery

• China is upper-middle income.
• But in 2025, GDP per person was about 239,000 yuan in Beijing and about 55,900 yuan in Gansu: over 4 times Gansu's.
• Disposable income per person: Beijing 89,090 yuan; Gansu 28,224 yuan.
• The national average hides a rich eastern core and a poorer western interior.

Voluntary internal migration

• People move by choice, mostly from rural to urban areas and from periphery to core.
• Push: low farm incomes, few jobs. Pull: wages, services, education.
• Migration is selective: most migrants are young adults of working age.

China's floating population

• Under China's hukou (household registration) system, a person's registered home can differ from where they live and work.
• China's 2020 census counted a floating population of 375.8 million: people living away from where their household is registered (excluding moves within the same city). Of these, 124.8 million had crossed a provincial border.
• China's urban share rose from 63.89% (2020) to 67.89% (end of 2025).

Megacity growth

• A megacity has 10 million people or more.
• UN, 2025: 33 megacities, up from 8 in 1975. 19 of the 33 are in Asia, and 37 are projected by 2050.
• Megacities grow by natural increase, by migration from the periphery, and by absorbing surrounding settlements. They often dominate their country (urban primacy).

Definitions change the numbers

• In 2025 the UN changed how it defines a city: a cluster of touching 1 km² grid cells, each with at least 1,500 people per km², holding at least 50,000 people in total.
• Before (2018), it used each country's own city boundaries.
• Under the new method Jakarta has about 42 million people in 2025. The 2018 definitions had projected about 12 million for 2025.

Mission 3: At today's rate, Niger's population would double in about 21 years. Japan's is shrinking. Why?

Births, deaths and natural increase

• Crude birth rate (CBR) and crude death rate (CDR): births and deaths per 1,000 people per year.
• Natural increase rate (NIR), as a % per year = (CBR − CDR) ÷ 10.
• Dividing by 10 turns "per 1,000" into "per 100".
• Total population change = natural change + net migration.

Two contrasting countries

Niger is a low-income country; Japan is high income.

Fertility and replacement level

• Total fertility rate (TFR): the average number of children a woman would have if she survived to age 50 and had children at today's rates for each age.
• Replacement level is about 2.1 where few children die, and higher where child mortality is high.
• It is above 2 because some children die before adulthood and slightly more boys than girls are born.
• World TFR in 2024: 2.25.

Life expectancy

• Life expectancy at birth: the average number of years a newborn would live if today's death rates at each age stayed the same.
• World in 2024: 73.3 years. Niger 61.4; Japan 84.9.
• It is a summary of today's death rates, not a forecast for any one person.

The demographic transition model (DTM)

• Stage 1: high, fluctuating birth and death rates; little or no growth.
• Stage 2: death rates fall (better food supply, clean water, sanitation, vaccination); birth rates stay high, so growth is rapid.
• Stage 3: birth rates fall (fewer child deaths, urbanisation, girls' education, contraception, the cost of raising children); growth slows.
• Stage 4: low birth and death rates; slow or no growth.
• Stage 5 (added later): births below deaths; the population falls.

Using and criticising the DTM

• Niger fits late stage 2: its death rate is already low, but its birth rate is still very high.
• Japan fits stage 5: its population peaked in 2008. In 2025 there were 671,270 births and 1,589,533 deaths among Japanese nationals.

Limitations of the DTM

• It is based on the history of Western Europe and North America.
• In many lower-income countries, death rates fell quickly with imported medicine and public health, before economic development, so stage 2 growth was faster.
• It ignores migration, culture and policy (China's birth limits, for example).
• It does not predict when, or whether, a country moves on. Stage 5 was added later.

Population pyramids

• Bars show the % of the population in each 5-year age group, males on the left and females on the right.
• Niger: a wide base that narrows fast. 46.6% are under 15 and 2.6% are 65 or over.
• Japan: a narrow base and a bulge at older ages. 11.4% are under 15 and 29.8% are 65 or over.
• The shape records past births, deaths and migration.

The dependency ratio

• Dependency ratio = (people aged 0–14 + people aged 65+) ÷ people aged 15–64 × 100.
• It is the number of dependants for every 100 people of working age.
• Young and old dependency ratios can be calculated separately.
• Caution: many 15–19-year-olds are still studying, and many over-65s work.

Doubling time

• For steady percentage growth, doubling time ≈ 70 ÷ growth rate (% per year).
• This is the "rule of 70". It is an approximation that assumes the rate stays constant.

Population momentum

• Almost half of Niger's people are under 15. As they reach parenthood, births will stay high even if each woman has fewer children.
• This population momentum keeps a young population growing for decades after fertility starts to fall.
• Japan has the opposite momentum: small young cohorts mean fewer future parents.

Mission 4: Dhaka grew from 3 million people in 1980 to over 18 million by 2017. Who gains and who loses when a city grows that fast?

How big is Dhaka? It depends who is counting

• World Bank: over 18 million in 2017.
• 2022 census: the two Dhaka city corporations had about 10.3 million people.
• UN, 2018 method: 19.6 million in 2018.
• UN, 2025 method: 36.6 million in 2025, second only to Jakarta. With the 2018 definitions, the 2025 figure would be about 25 million.
• Same place, different boundaries. Always name the source and the definition.

Why Dhaka grows

• Natural increase plus rural–urban migration from across Bangladesh.
• Greater Dhaka holds 36% of Bangladesh's urban population.
• Push: low rural incomes and hazards. IOM research links some of this migration to climate stress.

The pull of garment jobs

• Pull: jobs. The ready-made garment (RMG) industry directly employs about 4.2 million people, roughly 60% of them women. RMG made up 80.6% of Bangladesh's exports in 2025–26.

Consequences for individuals: opportunity

• Work: factory and service jobs bring regular wages. Garment work is a major source of paid work for women.
• Money home: migrants can send part of their earnings back to rural families.
• Services: schools, clinics and colleges are closer at hand than in many rural areas.

Consequences for individuals: costs

• Housing: many migrants live in informal settlements. The 2022 census counted 692,628 slum dwellers in Dhaka district; the World Bank put Dhaka's figure at about 3.5 million in 2017. Definitions differ again.

Consequences for individuals: safety and time

• Safety: in 2013 the Rana Plaza building collapsed. More than 1,100 people died and more than 2,500 were injured. The ILO's follow-up focuses on safety in the garment industry.
• Time: average traffic speed fell from 21 km/h to 7 km/h in ten years (World Bank press release, July 2017).

Consequences for society and the environment

• Economy: congestion wastes about 3.2 million working hours a day.
• Environment: between 1960 and 2008, Dhaka's water bodies shrank by 32.6% and its low-lying land by 52.6%. These areas acted as natural reservoirs and drainage for storm water.
• Governance: water, transport, housing and waste services struggle to keep pace with growth.

Responses

• Transport: Dhaka's first metro, MRT Line 6, partly opened in December 2022.
• Pollution: tanneries are being moved out of Hazaribagh, in the city, to a tannery estate at Savar.
• Exam move: a case study earns more credit when it includes management responses and judges how far they reduce the costs of growth.

Exam move: weighing consequences (AO3)

• Sort the consequences by who is affected (migrants, established residents, businesses, the state), by type (economic, social, environmental) and by time (short or long term).
• Benefits and costs often fall on different people. The national economy gains export earnings, while workers carry much of the risk.
• Finish with a judgement: for whom, and under what conditions, does megacity growth bring more benefits than costs?

Mission 5: Within a year of August 2017, nearly 725,000 people had fled from Myanmar into Bangladesh. Why do so many people flee at once, and what happens where they arrive?

Forced and voluntary migration

• Forced migration: people are compelled to leave by threats to life or livelihood, such as conflict, persecution or disaster.
• In practice it is a continuum: many moves mix choice and compulsion.
• Push factors may be political (conflict, persecution) or environmental, either sudden (floods, storms) or slow (drought, sea-level rise). Development projects such as dams also displace people.

Who is who

• Refugee: outside their own country, owing to a well-founded fear of being persecuted for reasons of race, religion, nationality, membership of a particular social group or political opinion (1951 Convention, extended by the 1967 Protocol).
• Asylum-seeker: has applied for protection, and the claim is not yet decided.
• Internally displaced person (IDP): forced to flee home but has not crossed an international border.
• People displaced by disasters are not refugees under the Convention. "Climate refugee" is a media term, not a legal status.

Global figures

• End of 2025: 117.8 million people were forcibly displaced, the first fall in a decade.
• They include 41.6 million refugees, almost 9 million asylum-seekers and 68.7 million people displaced inside their own country by conflict.

Stocks and flows

• IDMC counted more than 82.2 million IDPs at the end of 2025: 68.6 million from conflict (UNHCR rounds this to 68.7) and 13.6 million from disasters.
• These are stocks: people displaced at one moment. IDMC also counts flows: 62.2 million displacements during 2025, including repeat moves by the same people.

Political push: the Rohingya

• On 25 August 2017 the Arakan Rohingya Salvation Army (ARSA) attacked a military base and up to 30 security posts in northern Rakhine State.
• Myanmar's security forces then began "clearance operations".
• A UN fact-finding mission found the response "immediate, brutal and grossly disproportionate", and that it "targeted and terrorized the entire Rohingya population".
• By mid-August 2018, nearly 725,000 Rohingya had fled to Bangladesh.

Root causes and the place left behind

• The mission found most Rohingya "de facto stateless, arbitrarily deprived of nationality", after decades of increasingly exclusionary citizenship laws.
• At least 392 villages, 40% of all settlements in northern Rakhine, were partly or totally destroyed.
• Long-term causes (no citizenship, exclusion) made the community vulnerable; the 2017 operations were the trigger.
• Bangladesh is not a party to the 1951 Convention and calls the Rohingya "Forcibly Displaced Myanmar Nationals"; UNHCR counts them as refugees.
• On 30 September 2026, Bangladesh hosted 1,206,528 Rohingya refugees, including people who arrived after renewed violence from 2024.

Consequences for the refugees

• Refugees: life in camps that depend on aid. The Kutupalong–Balukhali camps sheltered more than 600,000 people in 2021, the world's largest refugee camp at the time; a massive fire swept them in March 2021.

Consequences for the host area

• Host area (Cox's Bazar):
  • About 4,818 acres of forest reserve were destroyed (Forest Department estimate).
  • Wages for agricultural and other unskilled work were depressed.
  • UNDP estimates that, because of falling wages, headcount poverty rose by 2.73 percentage points in Teknaf and 2.63 in Ukhiya.
• Not everyone lost. UNDP's full report says low wages help large farmers who hire labourers, price rises can benefit traders, and hotels, restaurants and transport businesses gain from extra demand; it names day labourers as a vulnerable group.
• Host country: a long-term humanitarian commitment, with no quick return in sight.

Environmental push: Pakistan's floods, 2022 — causes

• The government's needs assessment reports Pakistan's wettest August since 1961. In Sindh and Balochistan, rainfall was six and seven times the average monthly totals.
• The same assessment cites attribution research: the heaviest five-day rainfall in these provinces was about 75% more intense than it would have been without 1.2 °C of warming.
• Vulnerability turned extreme rain into disaster: millions lived and farmed on the Indus plains, many in homes that could not withstand floodwater.
• Note: the attribution study itself (World Weather Attribution) reports 7 and 8 times the usual monthly totals.

Pakistan's floods: scale and consequences

• Extreme monsoon floods affected about 33 million people, one in seven Pakistanis. Nearly 8 million were displaced and more than 1,700 died.
• IDMC recorded 8.2 million displacements, "the world's largest disaster displacement event in the last ten years". More than 1 million people were still displaced in December 2022.
• About 780,000 houses were destroyed (preliminary assessment, October 2022). Damage came to US$14.9 billion and economic losses to US$15.2 billion. Total recovery needs are estimated at US$16.3 billion.
• The government's assessment says "one-third of the country has been under water". IDMC, citing UNOSAT satellite data, gives about 85,000 km² at the peak: about 10% of the country. Check how each figure was measured.

Slow-onset environmental push

• Drought, sea-level rise and salty groundwater push people gradually, and often look like economic migration.
• The World Bank projects up to 216 million internal climate migrants by 2050 across six world regions in its pessimistic scenario, including up to 19.9 million in Bangladesh.
• These are model projections, not counts. Say so when you use them.

Categorising consequences (skills)

• Group consequences by place (origin, destination), people (migrants, host communities) and type (social, economic, environmental, political).
• A table or flow diagram makes patterns easy to see. The guide asks how impacts "can be categorized and represented graphically".

Mission 6: From 1980 China limited most couples to one child. By 2021 it allowed three. Why the U-turn, and can governments change how many children people have?

Global trends in family size

• World fertility fell from 3.31 children per woman in 1990 to 2.25 in 2024.
• The world's 8.2 billion people are projected to peak at about 10.3 billion in the mid-2080s.
• Fertility has fallen in every region since 1990. Sub-Saharan Africa is still highest (4.26) and Eastern and South-Eastern Asia lowest (1.34).
• Within regions the range is wider still: Niger 5.94, Japan 1.22; South Korea 0.75. (South Korea: 0.80 in 2025.)

Sex ratios

• Sex ratio at birth (SRB): boys born for every 100 girls. Around 105 is expected, and 103–107 is the usual range.
• China's SRB was 111.3 in the 2020 census, down 6.8 since 2010.
• India counts girls per 1,000 boys. Its 2019–21 survey found 929 girls per 1,000 boys for recent births, or about 108 boys per 100 girls. Its child sex ratio (aged 0–6) was 918 girls per 1,000 boys in 2011.
• Skewed ratios result from sex-selective abortion, driven by son preference together with prenatal sex-determination technology and fewer births per family.

Ageing ("greying")

• Globally, people aged 65+ are projected to outnumber children under 18 by the late 2070s.
• In September 2026, a record 29.6% of Japan's people were aged 65 or over: 36.2 million people. (National figures differ slightly from the UN figure on 3.11.)
• Pressures: pensions, health care and long-term care, and fewer workers per older person.
• Opportunities: older people's spending, work and volunteering.

Policies for an ageing society: Japan

• Care: Long-Term Care Insurance, from April 2000, funds care services.
• Working longer: from April 2021, employers must make efforts to secure work for people up to age 70.
• Migration: the Specified Skilled Worker status, from April 2019, admits foreign workers to sectors short of labour.
• These ease the costs of ageing but do not reverse it.

From anti-natalist to pro-natalist: China

• 1980: the government began limiting most couples to one child, an anti-natalist policy.
• 2016: two children for all couples (law amended December 2015, in force 1 January 2016).
• 2021: three children allowed; the law was amended in August 2021.
• 2025: a national childcare subsidy of 3,600 yuan a year for each child under 3.

Why China changed course

• China's working-age population (15–59) fell by 3.45 million in 2012, and officials describe it as shrinking year by year.
• The 2020 census found a total fertility rate of 1.3, which officials called "a low level".
• Since 2022 deaths have exceeded births. In 2025 there were 7.92 million births and 11.31 million deaths, and the population was 1,404.89 million.

Did the one-child policy cause the fall? (AO3)

• China's fertility had already fallen from about 6.1 in 1970 to about 2.7 in 1979, before the 1980 policy.
• The 1970s "later, longer, fewer" campaign (later marriage, longer gaps between births, fewer children) came first.
• So the one-child policy added to a fall already under way, alongside economic change and education.
• Exam move: "To what extent…" answers weigh a policy against the other causes, with dated evidence.

A pro-natalist policy: South Korea

• Fertility: 0.72 in 2023, 0.75 in 2024, 0.80 in 2025. Still far below 2.1.
• Measures: a child allowance extended to age 8, more publicly funded childcare, and longer parental leave: from February 2025, up to 18 months per parent if both take at least 3 months.
• The OECD says these policies "have not succeeded in reversing the fertility trend". Spending on family benefits was 1.5% of GDP in 2020, against an OECD average of 2.3%.

Do pro-natalist policies work? (AO3)

• UN review: child and family allowances have "a positive but weak effect"; short-term baby bonuses have "a limited effect, mostly affecting the timing of childbearing".
• A research review finds parental leave and childcare have stronger effects than cash.
• UNFPA warns that "simplistic or coercive" responses, such as baby bonuses or fertility targets, are "largely ineffective".
• Its 2025 report links falling birth rates to the cost of living, gender norms and fear of the future.

Gender-equality policy

• Gender equality: Rwanda's constitution requires women to hold at least 30% of posts in decision-making bodies. Women hold 63.8% of seats in its Chamber of Deputies.
• Gender inequality, workplace norms and limits on reproductive choice shape family-size decisions.
• India bans prenatal sex selection (PCPNDT Act, 1994). Its Beti Bachao Beti Padhao scheme (2015) targets the declining child sex ratio.

Anti-trafficking: the international framework

• Anti-trafficking: the UN Palermo Protocol, adopted in 2000 and in force since 2003, commits countries to prevent, suppress and punish trafficking in persons, especially women and children. It has 185 parties.
• A UNFPA workshop on skewed sex ratios lists expected consequences including "a marriage market squeeze, migration, trafficking": one link between population change and trafficking.

A national anti-trafficking policy: China

• China's Action Plan against Human Trafficking (2021–2030) was issued by the State Council's General Office in April 2021:
  • marriage-registration staff must report signs of trafficking;
  • identity and border-crossing records are cross-checked for cross-border marriages;
  • designated hospitals give rescued victims medical care and counselling.

Mission 7: Can a falling birth rate make a country richer?

The demographic dividend

• UNFPA: "the economic growth potential that can result from shifts in a population's age structure, mainly when the share of the working-age population (15 to 64) is larger than the non-working-age share of the population".
• The key word is potential: the gain is not automatic.

How the dividend works

• Fertility falls, so there are fewer children for each worker, and the dependency ratio falls.
• With more workers per dependant there can be more saving and investment, more women in paid work, and more spending on each child's health and education.
• Conditions: enough jobs, healthy and educated workers, and good governance. Without them, a large cohort of young adults may have no work.
• The first dividend comes from more workers per dependant. A possible second dividend comes from the savings of a large cohort preparing for old age.

The evidence from East Asia

• Bloom and Williamson estimated that population change added 1.4–1.9 percentage points a year to East Asia's growth in GDP per person between 1965 and 1990.
• That is as much as one-third of the observed growth.

Case study: Bangladesh

• Fertility fell from 6.82 children per woman (1972) to 2.14 (2024).
• In 2024, 65.5% of people were of working age (15–64).
• The age-dependency ratio was 93 in 1980. Calculate today's in a moment.

Why Bangladesh's fertility fell

• Family planning went door to door: female field workers visited women at home.
• From 1994 a nationwide stipend paid girls in rural areas to stay in secondary school (grades 6–10), on condition they stayed unmarried.
• Alongside these, more women entered paid work, much of it in the garment industry.

Bangladesh: jobs for the larger workforce

• Jobs for the larger workforce: the garment industry employed about 4.2 million people directly in 2020, roughly 60% of them women.
• Female labour-force participation was 42.68% in 2022 (BBS Labour Force Survey).

How long will Bangladesh's window last?

• The World Bank (2021), using UN projections from 2019, expected the window to close around 2033. The newer UN data (2024) has the working-age share still rising until about 2045: projections change.
• UNFPA Bangladesh says the first dividend, driven by the rising working-age share, peaked in the early 2020s.
• Risks: too few productive jobs for young people, and dependence on one export industry (garments made up 80.6% of exports in 2025–26).

Population and power between countries (synthesis)

• Between countries: India overtook China as the most populous country around 2022–23. The UN projected April 2023 at the time; its 2024 estimates put the crossover in mid-2022. A large workforce and market can bring influence, but only with jobs and skills.
• Workforces are shifting: Japan's population has been falling since 2008, while Niger's would double in about 21 years at today's natural increase.

Power within countries and between groups

• Within countries: as the share of older people grows, so does the share of older voters, and with it their weight in decisions on pensions and health care.
• Between groups: gender-equality policy can shift power. Rwanda's constitutional quota helped women win 63.8% of seats in its Chamber of Deputies.
• Exam move: name the scale (local, national, international) and the groups whose power changes.

How Unit 1 is examined (Paper 2)

• Paper 2: 1 hour 15 minutes, 50 marks. That is 40% of the grade at SL and 25% at HL.
• Section A: a structured question on each core unit (30 marks in total). Section B: an infographic or visual stimulus with structured questions (10 marks). Section C: one 10-mark extended answer from a choice of two.

What the top band rewards (Section C, 9–10 marks)

• Answers the question set: the topic and the command term.
• Evidence (examples, statistics, details) is integrated and explained, not listed.
• Evaluation weighs other perspectives and the strengths and weaknesses of evidence: the source, the definition and the date, as with Dhaka's three populations or Pakistan's "one-third".
• The conclusion is balanced and matches the evidence. Diagrams are annotated and support the argument.

The big ideas

• Physical factors set the limits of where people live; human factors decide within them (the Hu Line; the Nile).
• Development is classified by income (World Bank) or more broadly (HDI). National averages hide core–periphery gaps, which drive internal migration.
• Births, deaths and fertility drive the DTM; pyramids and dependency ratios show the results (Niger and Japan).
• Megacity growth brings jobs, but its costs fall unevenly (Dhaka).
• Forced migration: political (Rohingya, refugees) and environmental (Pakistan 2022, IDPs). Know stocks from flows.
• Policies on ageing, fertility, gender and trafficking: judge what the evidence shows.
• The demographic dividend is a time-limited potential (Bangladesh).

Final screen. Score, the mission list ticked, and "Next: test yourself in the Verify stage" (links to the Verify quiz).