Must-know sheet

Human Geography must-know sheet

The models, formulas and key terms you should know cold for AP Human Geography, with what each model shows and where it falls short. The real exam gives you no formula sheet and doesn't allow a calculator, so memorize the few formulas here and practice explaining every model at more than one scale.

Population math: the formulas to know

Unit 2

Arithmetic density = total population ÷ total land area: People per square kilometer (or mile) of all land. It's easy to work out but hides where people actually live, so it says little about pressure on farmland.
Physiological density = population ÷ arable (farmable) land: Shows how much pressure people put on the land that can grow food. It's far higher than arithmetic density where little land can be farmed, as in Egypt, where nearly everyone lives in the Nile valley and delta.
Agricultural density = number of farmers ÷ arable land: A high value means many farmers working small plots, which is typical of less mechanized farming in lower-income countries. A low value points to machines and large farms, as in the United States.
Density worked example: 10 million people, 500,000 km² of land, 50,000 km² of farmland and 2 million farmers give an arithmetic density of 20 per km², a physiological density of 200 per km² and an agricultural density of 40 per km². Comparing them tells you whether farmland is crowded and whether farming relies on people or machines.
Crude birth rate (CBR): Live births per 1,000 people in a year. 30,000 births in a country of 1 million people is a CBR of 30.
Crude death rate (CDR): Deaths per 1,000 people in a year. It's "crude" because it ignores age: an older country like Japan can have a higher CDR than a young, lower-income country even though its health care is better.
Rate of natural increase (RNI, %) = (CBR − CDR) ÷ 10: Births minus deaths per 1,000, turned into a percent. A CBR of 30 and a CDR of 10 give 20 per 1,000, or 2.0% a year. RNI leaves out migration.
Population growth = natural increase + net migration: Net migration is immigrants minus emigrants. A country can still grow when deaths outnumber births if enough people move in; Germany has had more deaths than births every year since 1972, yet it has more people today than it did then because of immigration (its population dipped in 2025 when immigration slowed).
Net migration rate: (Immigrants − emigrants) per 1,000 people in a year. Positive means more people arrive than leave.
Doubling time ≈ 70 ÷ growth rate (%): The rule of 70. At 2% a year a population doubles in about 35 years; at 1%, about 70 years. It assumes the rate stays the same, which it rarely does.
Total fertility rate (TFR): The average number of children a woman would have in her lifetime at today's birth rates for each age. It's the best single predictor of future growth: Niger's is around 6, while South Korea's fell below 1 (about 0.75 in 2024), among the lowest ever recorded.
Replacement-level fertility ≈ 2.1: Two children replace the parents; the extra 0.1 covers children who die young and the fact that slightly more boys than girls are born. It's higher where child mortality is high. A TFR below it for decades shrinks a population unless immigration fills the gap.
Infant mortality rate (IMR): Deaths of babies under age 1 per 1,000 live births. It's one of the clearest signs of health care, clean water and development.
Life expectancy: The average number of years a newborn can expect to live at current death rates. It rises as a country moves through the demographic and epidemiological transitions.
Dependency ratio = (ages 0–14 + ages 65 and older) ÷ ages 15–64 × 100: How many dependents each 100 working-age people support. 30 million children plus 10 million older people with 50 million working-age adults gives a ratio of 80. Young and aging countries can both score high, but one needs schools and the other pensions and elder care.
Sex ratio = males per 100 females: About 105 at birth almost everywhere. Higher ratios can reflect son preference, as in China and India, and very high working-age ratios in Gulf states like Qatar and the UAE reflect male migrant workers. Older age groups usually have more women because women live longer.
Percent change = (new − old) ÷ old × 100: Use it for any change over time. A population that grows from 40 million to 50 million has grown 25%. The exam allows no calculator, so the numbers are kept simple.

Scale and using models on the exam

Units 1, 2, 3, 4, 5, 6, 7

Four scales of analysis: Global (the whole world), regional (a group of countries like Southeast Asia, or a large part of one country), national (one country) and local (a city, county or neighborhood). At least two of the three free-response questions ask you to analyze across scales.
Why scale changes the story: Data averaged over a big area hide differences inside it. A country can look wealthy on average while a map of its counties shows deep gaps between rich and poor places, and a state-level election map looks very different from a county-level one.
Answering a scale question: Name the scale, describe the pattern you see at that scale, then explain what a different scale would show and why. For example, migration looks like a flow between countries at the global scale but like rural-to-urban moves at the national scale.
One process, many scales: Many topics work at several scales at once. Gerrymandering shapes local, state and national results; globalization ties a local farm or factory to world markets; a policy made nationally plays out differently in each region.
What a model is: A simplified picture of how something works, built on assumptions such as flat land, one market or one city's history. Models help you compare real places and explain patterns, but no real place fits one exactly.
Explaining a model's limitation: Name the assumption, say why it doesn't hold in a real place, and give an example. For instance: the concentric zone model assumes a city grows evenly outward from one center, but cars and highways created suburban business centers, as the multiple nuclei model shows.
Explaining a model's strength: Say what the model explains well and where it fits. The demographic transition model, for example, explains why death rates usually fall before birth rates, which matches the history of Europe and many other countries.
Reading a source: Before you explain a map, graph, table or photo, note its title, scale, units, date and place. Then describe the pattern or trend and explain the cause or effect the question asks for.
Task verbs: Identify means name it briefly; define means give its meaning; describe means give the relevant features; explain means give the how or why with reasoning or an example; compare means give similarities or differences.
Exam format: Section I is 60 multiple-choice questions in 60 minutes; Section II is three free-response questions, 7 points each, in 75 minutes: one with no source, one with one source and one with two. Each section is half your score, and there's no formula sheet or calculator.

Unit 1: maps, data and spatial concepts

Unit 1

Reference map: Shows where things are, such as borders, roads, cities and rivers. Atlases, road maps and political maps are reference maps.
Thematic map: Shows the pattern of one topic, such as population density, income or election results. The main kinds are choropleth, dot density, graduated symbol, isoline and cartogram.
Choropleth map: Shades whole areas, such as countries or counties, by a data value. Use rates or percentages, not raw totals, and remember that one color per area hides variation inside it.
Dot density map: Each dot stands for a set number of something, such as 1,000 people, so clusters and empty areas are easy to see.
Graduated (proportional) symbol map: Symbols such as circles get bigger as the value gets bigger, which suits totals like a city's population.
Isoline map: Lines connect points with the same value, such as elevation (contour lines) or temperature. Lines close together mean a rapid change.
Cartogram: Resizes countries or regions by a data value, such as population, so they look distorted on purpose. On a population cartogram, India and China swell and Canada and Russia shrink.
Map projection: Every flat map of the round Earth distorts at least one of shape, area, distance or direction. Choose the projection that keeps what you need.
Mercator projection: Keeps directions and local shapes true, so a straight line is a constant compass bearing, which is why it was made for navigation. It badly enlarges areas far from the equator: Greenland looks as big as Africa, but Africa is about 14 times larger.
Equal-area projections (Gall–Peters, Goode homolosine): Keep the sizes of places correct. Gall–Peters stretches shapes; Goode homolosine cuts the oceans apart (it's interrupted) to keep land shapes better, which makes distances across the gaps hard to measure.
Robinson projection: A compromise that distorts everything a little and nothing badly, so it's common on world wall maps. Nothing on it is perfectly true.
Map scale vs. scale of analysis: Map scale is the ratio of map distance to ground distance. A large-scale map (1:24,000) shows a small area in great detail; a small-scale map (1:10,000,000) shows a big area with little detail. Scale of analysis is the level you study, from global to local.
Absolute vs. relative distance: Absolute distance is measured in miles or kilometers. Relative distance is measured in time, cost or connection, such as "a two-hour flight".
Absolute vs. relative direction: Absolute direction uses north, south, east and west. Relative direction is based on a reference point or experience, such as "left" or "out west".
Clustering vs. dispersal: Clustered features are grouped close together; dispersed features are spread out. Describing the pattern is often the first step on a map question.
Geospatial technologies: GPS, GIS, remote sensing: GPS finds an exact location with satellites. Remote sensing collects images or data from satellites or aircraft. A GIS layers different data sets on one map so you can compare them. Online mapping tools such as Google Maps put these technologies in everyone's hands.
Field observation, surveys and interviews: Data gathered first-hand by watching, counting, asking questions or photographing a place. Travel accounts, news, policy documents and personal stories are other sources of spatial information.
Quantitative vs. qualitative data: Quantitative data are numbers, such as census counts. Qualitative data are descriptions, such as interviews or photos. Using both gives a fuller picture.
Census: An official count of a population. The U.S. census is taken every 10 years and is used to divide the 435 House seats among the states and to guide federal spending.
Absolute vs. relative location: Absolute location is an exact position, such as latitude and longitude. Relative location describes a place compared with other places, such as "just south of the Canadian border".
Place vs. space: Place is what makes a location unique: its physical and human traits and what it means to people. Space is the area between things and how they're arranged.
Flows: Movements of people, goods, money and ideas between places. Flows link places into networks.
Distance decay: Interaction between places drops as the distance between them grows. You visit, call and trade more with nearby places.
Time-space compression: Technology such as jet travel, phones and the internet shrinks the time it takes to connect places, so distance matters less. It weakens distance decay.
Sustainability: Using resources to meet today's needs without ruining them for the future. Geographers ask whether land and resource use can last.
Environmental determinism: The rejected idea that climate and landforms decide how advanced a society becomes. Geographers dropped it because it ignored human choice and was used to justify racist and colonial claims.
Possibilism: The idea that the environment sets limits and offers options, but people decide how to use them. It replaced environmental determinism.
Formal (uniform) region: An area where most people share a trait, such as a language, religion, climate or government. Its borders are drawn by data, like a country or the Corn Belt.
Functional (nodal) region: An area organized around a central point (node) and the connections to it, such as a city's commuting area, a newspaper's delivery area or a TV station's broadcast range.
Perceptual (vernacular) region: A region that exists in people's minds and feelings, such as the American South or the Midwest. Its borders differ from person to person.
Regional boundaries: Most regions have fuzzy edges (transition zones), overlap with other regions and are often argued over. A place can belong to several regions at once.

Population and migration models

Unit 2

Demographic transition model (DTM): Shows how birth and death rates change as a country develops: death rates fall first, so the population booms, and then birth rates fall and growth slows. It's based mainly on the history of Europe and North America.
DTM stage 1: high and stable: High birth and death rates and very slow growth. No country is in stage 1 today; a few isolated groups come closest.
DTM stage 2: death rates fall: Better food, clean water, sanitation and medicine cut death rates while birth rates stay high, so growth is fastest. Some countries in sub-Saharan Africa, such as Niger, are often placed here.
DTM stage 3: birth rates fall: Birth rates drop as people move to cities, children cost more to raise, women gain education and jobs and contraception spreads. Growth slows; India and Mexico are often placed here.
DTM stage 4: low and stable: Low birth and death rates and growth near zero. The United States and much of Western Europe are often placed here.
Possible DTM stage 5: decline: Not in the original model. Birth rates fall below death rates and the population shrinks and ages, as in Japan, South Korea and Italy.
Limits of the DTM: It's based on Europe's past and assumes every country will follow it; it can't predict when a country moves between stages; it leaves out migration; and it ignores government policy, culture and religion. Many countries' death rates fell much faster than Europe's because medicine was imported after 1950.
Epidemiological transition model (Omran, 1971): Explains how the main causes of death shift as a country develops, from infectious diseases to chronic (degenerative) ones. It pairs with the DTM: the drop in deaths in DTM stage 2 comes from beating infectious disease.
Epidemiological transition stages: Omran's three: 1. Pestilence and famine (infectious disease, like the Black Death). 2. Receding pandemics (sanitation and medicine cut deaths). 3. Degenerative diseases (heart disease, cancer). Later scholars added 4. Delayed degenerative diseases (medicine helps people live longer with them) and a proposed 5. Reemerging infectious diseases (antibiotic resistance, new viruses like COVID-19).
Malthusian theory (Thomas Malthus, 1798): Population grows geometrically (1, 2, 4, 8) while food supply grows arithmetically (1, 2, 3, 4), so people will outrun food. He expected famine, disease and war to check growth unless people had fewer children.
Limits of Malthus: He didn't foresee big jumps in farm output (the Second Agricultural Revolution and the Green Revolution) or the drop in birth rates as countries developed. Most hunger today comes from poverty, conflict and unequal distribution, not a global shortage of food.
Neo-Malthusians: Argue that Malthus's warning still matters, but widen it from food to water, energy, pollution and climate. Paul Ehrlich's The Population Bomb (1968) is a well-known example. Critics say technology and falling fertility keep proving the warnings too gloomy.
Ravenstein's laws of migration (1880s): Most migrants move short distances; long-distance migrants usually head for big cities; many move in steps; every flow produces a counterflow; city dwellers move less than rural people; and most migration is for economic reasons.
Ravenstein on gender: Women were more likely than men to migrate within their own country (short distances), and men were more likely to migrate internationally (long distances). Changing roles for women have changed these patterns since.
Push–pull model (Everett Lee): Migration results from push factors at the origin, pull factors at the destination, intervening obstacles between them and the migrant's own situation. People don't move just because a place is better; they weigh costs and barriers.
Limits of push–pull and Ravenstein: They treat people as free to choose, so they fit forced migration (refugees, slavery) poorly. Cheap travel, phones and the internet have also made long-distance and international moves far more common than in the 1880s.
Population pyramid: A bar graph of the share of males (left) and females (right) in each age group. Its shape shows past births and deaths and predicts future needs such as schools, jobs and elder care.
Expansive pyramid: A wide base that narrows quickly: many births, fast growth and a young population, as in Niger. Typical of DTM stage 2.
Stationary (column) pyramid: Similar-sized bars up to old age: low birth and death rates and slow growth. Typical of DTM stage 4.
Constrictive pyramid: A narrow base and a wider middle or top: falling births and an aging, possibly shrinking population, as in Japan. Typical of DTM stage 4 or 5.
Reading bulges and notches: A bulge is a baby boom moving up the pyramid; a notch is a period of few births or many deaths, from war, famine or a policy like China's one-child policy. An extra-wide bar of working-age men usually means male migrant workers.

Population, policy and migration terms

Unit 2

Population distribution: Where people live. Physical factors (climate, landforms, water) and human factors (jobs, history, culture, politics) explain why most people live in East Asia, South Asia and Europe and few live in deserts, high mountains or polar lands.
Most populous countries: India passed China as the most populous country in 2023, by UN estimates; together they hold more than a third of the world's roughly 8 billion people. China's population has been falling since 2022.
Carrying capacity: The largest population an area can support without damaging its resources. Going past it can cause soil loss, water shortages and food insecurity, though technology and trade can raise it.
Overpopulation: When a population is too large for an area's resources at its current level of technology. It depends on how resources are used, not just on head counts.
Consequences of distribution and density: Where people live shapes how easy it is to provide services like hospitals and schools, how political power and markets are spread, and how hard the land and water are pushed.
Pronatalist policy: Encourages births, such as paid parental leave, child payments, tax breaks or cheaper child care. France, Sweden, Hungary and Russia use them, usually with modest effects on birth rates.
Antinatalist policy: Discourages births. China's one-child policy ran from 1980 to 2015; China then allowed two children (2016) and three (2021), and now encourages more births. Side effects included a fast-aging population and a high sex ratio from son preference.
Immigration policy: Rules on who can move in and how many. Examples are quotas, which cap numbers by country or type, and Canada's points system, which favors education, skills and language.
Women and demographic change: When women have more access to education, paid work, health care and contraception, they tend to marry later and have fewer children. Bangladesh's TFR fell from almost 7 in the early 1970s to about 2 today.
Aging population: Happens when birth rates fall and people live longer, as in Japan (where almost 30% of people are 65 or older) and much of Europe. It can strain pensions and health care, cause labor shortages and give older voters more political weight.
Push and pull factors: Push factors drive people out of a place; pull factors draw them to a new one. Both can be economic (jobs), political (war, persecution), environmental (drought, floods), cultural (religious freedom) or demographic (a young, crowded job market).
Intervening obstacle: Something that blocks or slows a move, such as cost, distance, border controls, immigration laws or a mountain range.
Intervening opportunity: A closer place that offers what the migrant wanted, so they settle there instead of at the original destination.
Forced migration: Moving because of force or threat rather than choice. Examples include the Atlantic slave trade, which forced about 12.5 million Africans onto ships bound for the Americas (SlaveVoyages estimate), and people fleeing war or persecution.
Refugee: A person who has fled war, violence or persecution and crossed an international border to find safety. Under the 1951 Refugee Convention, persecution can be for race, religion, nationality, social group or political opinion. Large recent displacements include people from Syria, Afghanistan, Ukraine, Venezuela and Sudan.
Internally displaced person (IDP): Someone forced to flee home who stays inside their own country, so they don't have refugee status under international law.
Asylum seeker: Someone who has asked another country for protection and is waiting for a decision on whether they qualify as a refugee.
Voluntary migration types: Internal (within a country) or international; rural-to-urban; step migration (a series of smaller moves); chain migration (following relatives or neighbors who moved earlier); guest workers (temporary job migrants); transnational migrants (who keep strong ties to both countries).
Transhumance: Moving livestock with the seasons, such as to mountain pastures in summer and valleys in winter.
Guest workers: People allowed into a country to work for a limited time, such as Turkish workers in West Germany from 1961 or South Asian workers in Gulf states today.
Remittances: Money migrants send home. They're a big share of some economies, and India receives the most of any country, according to the World Bank.
Brain drain and brain gain: Brain drain is the loss of educated or skilled workers from a place; brain gain is the receiving place's benefit from them.
Ethnic enclave: A neighborhood where many people from one ethnic or immigrant group live, such as a Chinatown or Little Havana in Miami. Enclaves offer support and familiar culture but can also reflect segregation.
Effects of migration: Economic (filling jobs, remittances, brain drain), political (immigration debates and laws) and cultural (new foods, languages and religions, ethnic neighborhoods). Both the origin and the destination change.

Culture, language and religion

Unit 3

Culture and culture traits: Culture is a group's shared, learned way of life: beliefs, customs, tools and habits. A culture trait is one piece of it, such as a food, a building style or a way of using land.
Ethnocentrism vs. cultural relativism: Ethnocentrism judges other cultures by your own culture's standards. Cultural relativism tries to understand a culture on its own terms.
Cultural landscape: The visible mark people leave on the land: farms, buildings, places of worship, signs and land-use patterns. Ethnic neighborhoods, women's roles in the workforce and Indigenous lands also shape how space is used.
Traditional vs. postmodern architecture: Traditional architecture uses local materials and styles suited to the climate and culture. Postmodern architecture mixes styles and materials playfully and is common in global cities.
Sequent occupance: Layers left on a landscape by groups who lived there one after another. Istanbul's Hagia Sophia was a cathedral, became a mosque in 1453, a museum in 1934 and a mosque again in 2020.
Sense of place and placemaking: Sense of place is the feeling and meaning people attach to a place. Placemaking is shaping a space to reflect who lives there, through murals, festivals, gardens or signs in their language.
Ethnicity: Identity with a group that shares ancestry, culture, language or religion. Ethnic groups often cluster in neighborhoods and regions.
Centripetal and centrifugal forces (culture): Shared language, religion or ethnicity can unite a country (centripetal) or divide it (centrifugal), like the language split between Dutch-speaking Flanders and French-speaking Wallonia in Belgium.
Cultural hearth: The place where a culture trait, idea or innovation began, and from which it spreads.
Relocation diffusion: A trait spreads because people move and take it with them, such as Chinese food spreading with Chinese migrants. The trait isn't necessarily left stronger at home.
Expansion diffusion: A trait spreads outward from its hearth while staying strong where it began. It has three types: contagious, hierarchical and stimulus.
Contagious diffusion: Spreads person to person to nearby people, like a disease or a viral video, regardless of status.
Hierarchical diffusion: Spreads from powerful people or big cities down to smaller places, like fashion trends moving from world cities to smaller towns.
Stimulus diffusion: The core idea spreads but changes to fit the local culture, like McDonald's in India serving no beef.
Colonialism, imperialism and trade: Spread languages, religions and foods worldwide, which is why Spanish, English, French and Portuguese are spoken far from Europe and Christianity is widespread in the Americas and much of Africa.
Creolization, pidgin and creole: A pidgin is a simple mixed language for basic communication; a creole is a pidgin that has become a group's first language, like Haitian Creole (from French and West African languages). Creolization is any blending of cultures into something new.
Lingua franca: A shared language used to communicate across language lines, such as Swahili in East Africa or English worldwide today.
Time-space convergence: The time needed to travel or communicate between places keeps shrinking, so culture spreads faster. The internet and social media let trends like K-pop spread worldwide quickly.
Cultural convergence vs. divergence: Convergence is cultures becoming more alike through globalization. Divergence is groups protecting or reviving what makes them different, such as Quebec's 1977 law protecting the French language.
Language loss and revival: Globalization spreads English and other major languages, and many Indigenous and minority languages are disappearing. Some are being revived through schools and media, such as Welsh and Māori.
Acculturation vs. assimilation: Acculturation is adopting some traits of another culture while keeping your own. Assimilation is taking on the majority culture so fully that the original culture fades.
Syncretism: Blending traits from different cultures into something new, such as Mexico's Día de los Muertos, which mixes Indigenous traditions with Catholic holidays.
Multiculturalism: Many cultures living side by side while keeping their own identities. Canada made it official policy in 1971.
Folk vs. popular culture: Folk culture belongs to small, often rural, groups and changes slowly, spreading mostly by relocation. Popular culture is widespread, changes fast and spreads mostly by hierarchical and contagious diffusion through media.
Language family, branch, group and dialect: A family is languages with a shared ancient ancestor; branches and groups are closer relatives inside it (Romance is a branch of Indo-European). A dialect is a regional form of one language, with its own words, grammar or accent.
Isogloss: A boundary line on a map where a word or pronunciation changes, such as where people stop saying "soda" and start saying "pop".
Indo-European: The language family with the most native speakers. Branches include Germanic (English, German), Romance (Spanish, Portuguese, French, Italian), Balto-Slavic (Russian, Polish) and Indo-Iranian (Hindi, Bengali, Persian).
Other major language families: Sino-Tibetan (Mandarin and other Chinese languages, Burmese), Afro-Asiatic (Arabic, Hebrew, Amharic, Hausa), Niger-Congo (Swahili, Yoruba, Zulu), Austronesian (Indonesian, Malay, Tagalog, Malagasy, Māori) and Dravidian (Tamil, Telugu in southern India).
Most-spoken languages: Mandarin Chinese has the most native speakers; English has the most speakers overall when second-language speakers are counted.
Toponym: A place name. Toponyms record history and diffusion, like the Spanish names across the U.S. Southwest (Los Angeles, San Antonio) or names changed after independence.
Universalizing vs. ethnic religions: Universalizing religions seek converts everywhere and spread widely by expansion and relocation: Christianity, Islam, Buddhism and Sikhism. Ethnic religions are tied to one people and place and spread mainly when followers move: Hinduism and Judaism.
Christianity: Universalizing; hearth in the eastern Mediterranean (the Levant, around Jerusalem). It spread through the Roman Empire, helped by the conversion of Emperor Constantine (hierarchical), then by colonialism and missionaries. Main branches are Catholic, Protestant and Eastern Orthodox; it's the largest religion.
Islam: Universalizing; hearth in the Arabian Peninsula (Mecca and Medina) in the 600s CE. It spread by expansion, conquest and trade routes across North Africa, Southwest and South Asia and on to Southeast Asia; Indonesia and Pakistan now have the largest Muslim populations. Most Muslims are Sunni; Shia Muslims are the majority in a few countries, including Iran and Iraq.
Buddhism: Universalizing; hearth in northern India and Nepal about 2,500 years ago. It spread through missionaries and the Silk Roads, helped by Emperor Ashoka. Theravada is dominant in Sri Lanka and mainland Southeast Asia; Mahayana in China, Korea, Japan and Vietnam; Vajrayana in Tibet, Bhutan and Mongolia.
Sikhism: Universalizing; founded by Guru Nanak around 1500 in the Punjab region of India and Pakistan. Most Sikhs live in Punjab, with large communities abroad from relocation diffusion, and the Golden Temple in Amritsar is its holiest site.
Hinduism: Ethnic; hearth in South Asia (the Indus valley and Ganges plain), with no single founder. Most followers live in India and Nepal; it spread to places like Bali and later to South Asian communities abroad. Varanasi on the Ganges is a key sacred site.
Judaism: Ethnic and monotheistic; hearth in the eastern Mediterranean (the Levant). Its spread came mostly through relocation diffusion as Jews were dispersed (the diaspora). Jerusalem is sacred to Judaism, Christianity and Islam.
Religion on the landscape: Places of worship, sacred sites, cemeteries, pilgrimages and toponyms all mark the landscape. Respect each faith's own terms and avoid ranking religions.

States, nations and boundaries

Unit 4

State: An independent country with defined territory, a permanent population, a government and sovereignty. The UN has 193 member states.
Nation: A group of people who share a culture, history and identity and often want to govern themselves. A nation isn't the same as a state.
Nation-state: A state made up mostly of one nation. Japan and Iceland come close, though almost every state has some minority groups.
Multinational state: A state with two or more nations, such as the United Kingdom (English, Scottish and Welsh nations, plus people in Northern Ireland who identify as Irish or British) or Russia, home to many ethnic groups.
Multistate nation: A nation spread across more than one state, such as the Koreans in North and South Korea.
Stateless nation: A nation without a state of its own. The Kurds, numbering tens of millions across Turkey, Iraq, Iran and Syria, are often called the largest example.
Autonomous and semi-autonomous regions: Areas with partial self-rule inside a state, such as Greenland (part of the Kingdom of Denmark) and Native American reservations in the United States.
Sovereignty and self-determination: Sovereignty is a state's right to govern itself without outside control. Self-determination is the idea that a people should choose their own government; it drove the independence movements that created dozens of new states in Africa and Asia after World War II.
Colonialism and imperialism: Colonialism is taking control of and settling another territory; imperialism is extending power over other places by force, politics or economics. Together they drew many of today's borders.
Neocolonialism: When powerful countries or companies steer weaker states through money, debt and trade instead of direct rule.
Territoriality: People's attachment to their land and their efforts to control it, from a gang's turf to a state's borders.
Shatterbelt: A region split by internal divisions and pulled between outside powers, such as the Balkans in the 1990s or Eastern Europe during the Cold War.
Choke point: A narrow passage that gives leverage to whoever controls it: the Strait of Hormuz, the Strait of Malacca, the Suez Canal, the Panama Canal and the Bab el-Mandeb.
Antecedent boundary: Drawn before most people settled the area. The 49th parallel across the western U.S.–Canada border, set in 1818 and 1846 before most settlers arrived, is often given as an example.
Subsequent boundary: Drawn after people had settled an area, often to fit the cultural landscape that had already formed.
Consequent boundary: A kind of subsequent boundary drawn to follow cultural lines such as language or religion, like the 1947 India–Pakistan partition line based mainly on religion.
Superimposed boundary: Forced on an area by outside powers, ignoring the cultures already there, as with many African borders drawn by European colonizers.
Geometric boundary: A straight line, often following latitude or longitude, such as the 49th parallel between the U.S. and Canada or many borders in the Sahara.
Relict boundary: No longer works as a border but still leaves traces on the landscape, like the remains of the Berlin Wall or the old line between East and West Germany.
Defined, delimited, demarcated, administered: The steps in making a boundary: defined in a legal document, delimited (drawn) on a map, demarcated on the ground with fences, walls or markers, and administered by officials who enforce it.
Boundaries from war and outside decisions: The Korean DMZ was set by the 1953 armistice. At the Berlin Conference of 1884–85, European powers set rules for claiming Africa with no African leaders present.
UN Convention on the Law of the Sea (UNCLOS): Signed in 1982, in force since 1994. A country controls a 12-nautical-mile territorial sea, can enforce some laws out to 24 nautical miles, and has rights to fish, oil and gas in a 200-nautical-mile exclusive economic zone (EEZ). Beyond that are the high seas.
Maritime disputes: Overlapping EEZ claims cause conflict, as in the South China Sea, where an international tribunal ruled in 2016 against most of China's broad claims, which China rejects.
Reapportionment and redistricting: After each 10-year census, the 435 U.S. House seats are reapportioned (shared out) among states by population. States then redistrict, redrawing voting-district lines.
Gerrymandering: Drawing district lines to help one party or group. Packing crowds the other side's voters into a few districts; cracking splits them across many so they're outvoted everywhere.

Governance, devolution and supranationalism

Unit 4

Unitary state: Power is concentrated in the national government, which makes most decisions from the top down, as in France, Japan and China. It suits smaller or more uniform countries.
Federal state: Power is shared between the national government and states or provinces with their own powers, as in the United States, Germany, India, Nigeria, Brazil and Canada. It often suits large or culturally diverse countries.
Devolution: Power moves from the central government to regions. Examples: the UK created a Scottish Parliament and a Welsh assembly in 1999, Spain has 17 autonomous communities, and Belgium is divided into Flanders, Wallonia and Brussels.
Causes of devolution: Physical barriers that separate people, ethnic separatism, ethnic cleansing, terrorism, economic or social gaps between regions, and irredentism (see below). Wealthier regions such as Catalonia sometimes object to sending tax money to poorer ones.
Ethnic separatism: An ethnic group seeking more self-rule or independence, as in Catalonia (Spain), Quebec (Canada, with independence votes that failed in 1980 and 1995) and Scotland (independence rejected in 2014).
Ethnic cleansing: Forcibly removing or killing an ethnic group to make an area uniform, as in Bosnia in the 1990s during the breakup of Yugoslavia.
Irredentism: A state claiming land in another country where people of its own ethnicity live. Nazi Germany's claim to the Sudetenland in 1938 is the classic case; Russia used similar claims when it annexed Crimea from Ukraine in 2014, which most countries don't recognize.
States breaking apart: The Soviet Union split into 15 countries in 1991, largely along national lines; Yugoslavia broke up in the 1990s; Czechoslovakia split peacefully in 1993; and South Sudan became independent from Sudan in 2011.
Failed state: A state whose government can no longer provide basic security or services, such as Somalia after its central government collapsed in 1991.
Centrifugal forces (political): Forces that divide a state: uneven development, ethnic or religious conflict, separatist movements, poor infrastructure and distrust of government.
Centripetal forces (political): Forces that unite a state: shared identity, national symbols, fair investment in roads and services across regions, and a strong, trusted government.
Ethnonationalism: Strong loyalty to one's own ethnic nation. It can unite a state where most people share that identity but push minority groups away.
Communication technology and sovereignty: Phones, the internet and social media help people organize, whether for independence, democracy or closer ties between countries, and make it harder for governments to control information.
Democratization: The spread of democratic government, often bringing more local power and voice to regions.
Supranationalism: Countries joining organizations that work across borders on shared problems, trade and defense. Members gain cooperation but give up some freedom to act alone.
United Nations (UN): Founded in 1945 with 193 member states today. It works on peace, human rights, refugees and development.
European Union (EU): Economic and political union with 27 members since the UK left in 2020 (Brexit). Most members share the euro and allow free movement of people, goods and money.
NATO: A military alliance founded in 1949 in which an attack on one member counts as an attack on all. It has 32 members after Finland (2023) and Sweden (2024) joined.
Other supranational groups: ASEAN (Southeast Asia, 1967; Timor-Leste became its 11th member in 2025), the African Union (55 members), the Arctic Council (8 Arctic states) and trade groups like USMCA and Mercosur.

Agriculture: revolutions, hearths and models

Unit 5

First Agricultural Revolution (Neolithic): The domestication of plants and animals about 10,000–12,000 years ago, which let people settle in villages. It happened independently in several hearths.
Agricultural hearths: The Fertile Crescent was the earliest known (wheat, barley, sheep, goats). Others include the Indus River valley, East Asia's river valleys (rice, millet), Southeast Asia, Mesoamerica (maize, beans, squash), the Andes (potatoes, quinoa) and West Africa and the Sahel (sorghum, yams).
Columbian Exchange: After 1492, crops, animals and diseases moved between the Americas and the rest of the world. Maize, potatoes, tomatoes and cacao went to Europe, Africa and Asia; wheat, sugarcane, coffee, horses and cattle came to the Americas, along with diseases like smallpox that killed a huge share of Indigenous people.
Second Agricultural Revolution: Began in Britain and Western Europe in the 1700s alongside the Industrial Revolution: better crop rotation (such as the Norfolk four-course system), enclosure of fields, the seed drill, then steam- and gas-powered machines and railroads. Fewer farmers grew more food, freeing people to work in factories.
Green Revolution (Third Agricultural Revolution): Began in Mexico in the 1940s and spread to India, Pakistan and other parts of Asia in the 1960s, led by Norman Borlaug. High-yield wheat and rice seeds plus fertilizer, pesticides, irrigation and machinery raised yields sharply.
Limits of the Green Revolution: It needed costly inputs, so richer farmers gained most; it raised water and chemical use and reduced crop variety; and it had much less success in most of sub-Saharan Africa, where staple crops, soils and rainfall differed.
Von Thünen model (1826): Predicts rings of farming around one market town based on transport cost: market gardening and dairy closest, then forest (wood was heavy and needed for fuel), then grain and field crops, then ranching farthest out. Perishable or heavy goods are produced nearest the market.
Von Thünen's assumptions: One isolated market town, flat land with the same soil and climate everywhere, no roads or rivers (farmers haul goods straight to market), and farmers who choose the most profitable use.
Limits of von Thünen: Refrigeration, trucks and planes let perishable food travel far; roads, rivers and terrain bend the rings; wood is no longer the main fuel; and global markets, subsidies and specialty regions break the pattern. It still loosely fits at the global scale, with intensive farming near big markets.
Bid-rent theory (farming): Land closest to a market costs the most, so only uses that earn a lot per acre can afford it. That's why intensive farming sits near cities and extensive farming farther away; von Thünen's rings are a bid-rent pattern.
Clustered, dispersed and linear settlements: Clustered: homes grouped in a village with fields around it. Dispersed: farmhouses spread out, each on its own land, as in much of the U.S. Midwest. Linear: homes strung along a road, river or coast.
Metes and bounds: Land divided using natural features and distances, giving irregular plots, as in much of the original 13 colonies.
Township and range: A square grid laid over much of the central and western United States after the Land Ordinance of 1785: townships of 6 × 6 miles, each with 36 one-square-mile sections of 640 acres.
Long lots: Narrow strips running back from a river so each farm gets water access, laid out by French settlers in places like Quebec and Louisiana.

Farming types, systems and challenges

Unit 5

Intensive agriculture: Lots of labor or money on a small area to get high output: market gardening, plantations, mixed crop and livestock farming and wet rice farming.
Extensive agriculture: Little labor or money spread over a lot of land: shifting cultivation, nomadic herding and ranching.
Subsistence vs. commercial agriculture: Subsistence farming grows food mainly for the farmer's own family. Commercial farming raises crops and animals to sell, often on large, mechanized farms.
Climate and farming: Mediterranean farmers grow grapes, olives and citrus suited to hot, dry summers; wet rice needs warm, well-watered lowlands; plantations of coffee, bananas, sugarcane and cacao are in the tropics; ranching suits dry grasslands.
Market gardening (truck farming): Growing fruits, vegetables and flowers for nearby city markets. It's intensive and close to cities because the produce spoils quickly.
Plantation agriculture: Large commercial farms growing one cash crop, such as bananas, coffee, sugarcane or palm oil, mostly in the tropics, with roots in colonial times.
Mixed crop and livestock farming: Growing crops mainly to feed animals, which are sold, as in the U.S. Corn Belt.
Shifting cultivation and slash-and-burn: Farmers clear a forest plot, often by burning, farm it for a few years until the soil wears out, then move on and let it regrow. It can work at low population densities but causes deforestation when done at large scale or too often.
Nomadic herding (pastoral nomadism): Moving herds of animals such as camels, goats or cattle across dry lands to find water and grazing, as in parts of North Africa, Central Asia and the Sahel.
Ranching: Raising livestock on large areas of grassland for sale. It's extensive and found far from markets on cheap land.
Monoculture and monocropping: Monoculture is one crop covering a large area; monocropping is planting the same crop in a field year after year. Both are efficient but raise the risk from pests and price drops and wear out the soil.
Agribusiness: Large companies that control many steps of food production, from seeds and machinery to processing, shipping and selling.
Vertical integration: One company owning several steps of a commodity chain, such as a meat company that owns the farms, feed mills and processing plants.
Economies of scale: Producing each unit more cheaply as output grows. It's why small family farms have been merged into fewer, much larger farms in many richer countries.
Commodity chain: Every step a product goes through from farm to processor, shipper, store and buyer. Companies controlling key steps hold much of the power and profit.
Global system of agriculture: Food crosses many borders before it's eaten. Many lower-income countries depend on exporting one or two crops, such as coffee or cacao, so falling world prices hurt them, and subsidies in richer countries shape what farmers everywhere can sell.
Cash crop: A crop grown to sell rather than eat, often for export, such as coffee, cacao, cotton or tea.
Agricultural subsidy: Government payments to farmers. They can keep farms in business but encourage overproduction and make it hard for unsubsidized farmers in other countries to compete.
Environmental effects of farming: Clearing forests, draining wetlands, terracing hillsides and irrigating dry land reshape the landscape. Overgrazing can cause desertification, poorly drained irrigation can cause soil salinization, and fertilizer, pesticide and animal-waste runoff pollutes water.
Concentrated animal feeding operations (CAFOs): Large indoor livestock operations that produce cheap meat but concentrate animal waste, which can pollute air and water.
Genetically modified organisms (GMOs): Crops with altered genes to resist pests, survive weedkillers or raise yields. Major scientific reviews have found approved GM foods safe to eat; debates continue over seed costs, corporate control and biodiversity.
Value-added and specialty crops: Products made worth more by processing or by how they're grown, such as organic, fair trade or locally grown food, cheese or wine.
Fair trade: A certification system that guarantees farmers a minimum price and better working conditions for crops like coffee and cacao.
Local food, urban farming and community-supported agriculture (CSA): Ways to shorten the commodity chain. In a CSA, people pay a farm up front for a share of its harvest.
Aquaculture: Fish and seafood farming. It now supplies more than half of the fish and seafood people eat (FAO) but can pollute water and damage coastal habitats like mangroves.
Food insecurity and food deserts: Food insecurity is not having reliable access to enough healthy food. A food desert is an area, often low-income urban or rural, where fresh, healthy food is hard to reach. Other challenges to feeding the world include weak distribution systems, bad weather and farmland lost to suburbs.
Women in agriculture: Women do a large share of farm work worldwide, especially in lower-income countries, often unpaid or informal. They usually have less access to land ownership, credit, training and tools, and closing those gaps can raise harvests.

Cities: growth, systems and city-size models

Unit 6

Site vs. situation: Site is a city's physical setting, such as a harbor, river crossing or hilltop. Situation is its location relative to other places, such as trade routes and nearby cities. A city's situation can change; its site rarely does.
Urbanization: The growth in the share of people living in cities. Cities grow through migration and natural increase, and changes in farming, industry, transportation and communication have each pushed it forward.
Megacity and metacity: A megacity has 10 million or more people; a metacity has 20 million or more. Most fast urban growth today is in Asia and Africa.
Largest cities: By the UN's 2025 estimates, which use a new way of drawing city limits, Jakarta, Dhaka and Tokyo are the largest. Rankings change a lot depending on how a city's edge is defined.
Suburbanization and sprawl: Suburbanization is the growth of residential areas outside the central city, helped by cars, highways and cheap mortgages. Sprawl is spread-out, low-density, car-dependent growth onto open land.
Edge city: A new office and shopping hub at the edge of a metro area, usually near a highway interchange, such as Tysons, Virginia.
Exurb: A semi-rural area beyond the suburbs where many residents commute to the metro area.
Boomburb: A fast-growing suburban city of 100,000 or more people that isn't the main city of its metro, such as Mesa, Arizona.
World (global) city: A command center of the global economy, with major company headquarters, banks, stock exchanges and media, such as New York, London and Tokyo.
Urban hierarchy: Cities ranked by size and influence, from world cities down to small towns. New ideas and products often spread down this hierarchy (hierarchical diffusion).
Rank-size rule: Pₙ = P₁ ÷ n: The nth-largest city has about 1/n the population of the largest. If the largest has 12 million, the second has about 6 million, the third 4 million and the fourth 3 million. It fits countries with a well-developed network of cities, like the United States, fairly well.
Primate city: A city more than twice as large as the country's next-largest city, which dominates its economy, politics and culture, such as Bangkok, Paris or Lima. It often points to wealth and power concentrated in one place.
Gravity model: interaction ≈ (P₁ × P₂) ÷ d²: Predicts more movement of people, goods and calls between places that are bigger and closer. Doubling one population doubles the predicted interaction; doubling the distance cuts it to a quarter. Some versions divide by distance instead of distance squared.
Limits of the gravity model: It ignores borders, language, culture, income and how good the transportation links are, so two big, close cities split by a border or a mountain range interact less than it predicts.
Central place theory (Walter Christaller, 1933): Explains the size and spacing of towns that serve surrounding market areas. Many small towns offer everyday (low-order) goods, while fewer, bigger cities offer specialized (high-order) goods. Market areas are drawn as hexagons so they cover all the land without gaps or overlaps.
Range and threshold: Range is the farthest people will travel for a good or service. Threshold is the smallest number of customers needed to keep it in business. A hospital has a large range and threshold; a gas station has small ones.
Limits of central place theory: It assumes flat land, evenly spread people with equal incomes, equal travel in every direction and shoppers who always go to the nearest place. Terrain, highways, online shopping and uneven wealth all distort real patterns.
Bid-rent theory (cities): Land value and rent are highest at the most accessible spot, traditionally the central business district (CBD), and fall with distance. Offices and shops outbid factories and homes for central land, which is why the CBD has the tallest buildings.
Limits of bid-rent theory: Suburban business centers, zoning, highways and amenities like parks or views create several peaks of land value, not just one.

Models of the internal structure of cities

Unit 6

Concentric zone model (Ernest Burgess, 1920s Chicago): Five rings: the CBD; a zone of transition with factories, poor housing and new immigrants; working-class homes; middle-class homes; and a commuter zone. The city grows outward as groups move out and newer groups replace them.
Limits of the concentric zone model: It's based on one U.S. city before cars were common, and it ignores transportation routes, physical features and suburban business centers.
Sector model (Homer Hoyt, 1939): Land use forms wedges (sectors) along transportation routes such as rail lines, rivers and main roads. A high-rent residential sector stretches out from the CBD, and lower-income housing sits near industrial sectors along the rails.
Limits of the sector model: Also based on U.S. cities in the 1930s; it doesn't account for cars, suburban centers or more than one core.
Multiple nuclei model (Chauncy Harris and Edward Ullman, 1945): A city grows around several nodes, not just the CBD, such as a port, university, airport, industrial district or suburban business center. Some activities cluster together and others avoid each other.
Limits of the multiple nuclei model: It's based on U.S. car-oriented cities and doesn't predict where each node will form.
Galactic city model (peripheral model): A metro area where the old central city is surrounded by suburbs and edge cities linked by a ring road (beltway). Business activity spreads to the edges and the CBD becomes less important.
Limits of the galactic city model: It fits spread-out, car-based U.S. metros, not compact, transit-based cities, and it overlooks the revival of many downtowns.
Latin American city model (Griffin–Ford): A CBD with a commercial spine running out to an elite residential sector and mall. Around it are rings that get poorer outward: a zone of maturity, a zone of in situ accretion (partly improved housing) and a zone of peripheral squatter settlements. A disamenity sector of very poor housing reaches toward the center.
Key point about the Latin American model: The wealthy live near the center and along the spine, the reverse of the U.S. pattern, reflecting the Spanish colonial plaza layout. It doesn't fit every city and leaves out newer gated suburbs and edge growth.
African city model (Harm de Blij): Three CBDs: a colonial CBD (often with a grid layout), a traditional CBD and an open-air market zone. Around them are ethnic and mixed neighborhoods, a mining or manufacturing zone, and squatter settlements at the edges.
Limits of the African city model: Africa is very diverse, colonial histories differed, and many cities have grown far beyond the model's simple pattern.
Southeast Asian city model (Terry McGee): Centered on the old colonial port rather than a single CBD, with a government zone, a Western commercial zone and a commercial zone of mostly Chinese merchants, then mixed land-use and residential zones, new suburbs and squatter areas, market gardening at the edge, and new industrial estates.
Limits of the Southeast Asian model: It's based on port cities of the 1960s; many Southeast Asian cities now have modern CBDs, new towns and sprawling suburbs.
How to use urban models: Each model simplifies one region and era. Use them to compare and explain real cities, and on the exam name the model, describe its pattern and say where a real city fits or breaks it.

Urban land use, data and challenges

Unit 6

Low-, medium- and high-density housing: Low: detached single-family homes on their own lots. Medium: townhouses and duplexes. High: apartment buildings. Density usually rises toward the city center.
Zoning: Rules that set what can be built where, such as homes, shops or factories. Single-family-only zoning keeps density low and housing scarce.
Infilling: Building on empty or underused lots inside the city, adding homes without spreading outward.
Infrastructure: The shared systems a city runs on: roads, public transit, water and sewer lines, power grids and internet. Where it's built affects where businesses locate and which neighborhoods grow.
Smart growth: Planning that steers growth into compact, walkable areas near transit and protects open land.
New Urbanism: Designing walkable neighborhoods with mixed housing types, shops within walking distance and front porches facing the street, such as Seaside, Florida.
Mixed-use development: Combining homes, shops and offices in the same building or block, so people can walk to more places.
Transit-oriented development: Building dense housing and businesses around transit stations. Curitiba, Brazil, is known for its bus rapid transit system.
Greenbelt and urban growth boundary: A greenbelt is a ring of protected open land around a city, like London's. An urban growth boundary is a line beyond which development is limited, like Portland, Oregon's. Both slow sprawl but can raise housing prices inside.
Slow-growth policies and farmland protection: Limits on how fast a city can expand, and rules or payments that keep nearby farmland from being developed.
Limits of sustainable design: Smart growth, New Urbanism and growth boundaries can reduce sprawl, improve walkability and transit and widen housing choices. Critics say they can raise housing costs, lead to de facto segregation and erase a place's historic character.
Urban data: Quantitative data (census counts, income, age and housing surveys) and qualitative data (field observation, interviews, residents' stories) each show different things, so combining them gives the fullest picture of a neighborhood.
Redlining: Starting in the 1930s, government maps and lenders denied or limited home loans in neighborhoods with Black and immigrant residents. The Fair Housing Act of 1968 outlawed it, but its effects on wealth and housing remain.
Blockbusting: Real estate agents stirred up racial fears so white owners would sell cheaply, then resold the homes at higher prices, speeding up segregation.
Filtering: Older housing passes to lower-income residents over time, often getting split into smaller units or falling into disrepair.
Urban renewal: Clearing older, poor neighborhoods to rebuild them with highways, public housing or offices. It often displaced long-time residents, especially in communities of color.
Gentrification: Wealthier people moving into a lower-income neighborhood and fixing it up. It brings investment and services but raises rents and can displace long-time residents.
Affordable housing and inclusionary zoning: Housing costs are a major urban challenge. Inclusionary zoning requires new housing projects to include some units lower-income people can afford.
Disamenity zone: The poorest, least served parts of a city, often on steep slopes, flood plains or near dumps, with few services. Zones of abandonment are areas people and businesses have left, often with empty buildings.
Squatter (informal) settlements: Homes built without legal right to the land, often lacking water, sewers and power, such as Rio de Janeiro's favelas, Mumbai's Dharavi or Nairobi's Kibera. Residents often improve them over time.
Environmental injustice: Low-income and minority neighborhoods bearing more pollution and hazards, such as highways, factories and waste sites, than wealthier ones.
Fragmented local government: A metro area is split among many cities, counties, school districts and agencies, so problems that cross their borders, like traffic, housing and pollution, are hard to solve. Regional planning across a whole metro area is one response.
Urban sustainability challenges: Sprawl, gaps in sanitation, air and water pollution, energy use and climate risks like flooding and extreme heat.
Ecological footprint: The land and resources needed to support a population and absorb its waste. Cities' footprints reach far beyond their borders.
Brownfield: An old, polluted industrial site. Cleaning it up (remediation) and reusing it can revive a neighborhood without building on open land.

Development: measures and theories

Unit 7

Industrial Revolution: Began in Britain in the late 1700s, helped by coal, iron, the steam engine, money from trade and colonies, and growing markets. It spread to Western Europe, the U.S. and Japan, and industrial countries' hunger for raw materials and markets drove colonialism and imperialism.
Economic sectors: Primary: taking resources from the earth (farming, mining, fishing). Secondary: manufacturing. Tertiary: services (retail, health care). Quaternary: information and research. Quinary: top-level decision-making. As countries develop, jobs shift from primary to secondary to tertiary and beyond.
GDP (gross domestic product): The value of all goods and services produced inside a country in a year, no matter who owns the company.
GNP and GNI (gross national product, gross national income): Income earned by a country's people and companies, at home or abroad. Per capita means divided by the population, so countries of different sizes can be compared.
Formal vs. informal sector: The formal sector is taxed, regulated work. The informal sector is unregulated, untaxed work like street vending, which is a big share of jobs in many lower-income countries and doesn't show up fully in GDP.
Income distribution and the Gini coefficient: How evenly income is shared. The Gini coefficient runs from 0 (everyone has the same income) to 1 (one person has everything).
Social measures of development: Fertility rates, infant mortality, literacy, access to health care and the use of fossil fuels vs. renewable energy. They show quality of life that income alone misses.
Human Development Index (HDI): A UN index from 0 to 1 that combines health (life expectancy), education (years of schooling) and income (GNI per capita). Higher means more developed.
Gender Inequality Index (GII): A UN index of gaps between women and men in reproductive health (maternal mortality, teen births), empowerment (seats in parliament, secondary education) and the job market. Higher means more inequality.
Women and economic development: Women often gain education and paid work as countries develop, but they still earn less than men in most places and face legal and social barriers.
Microloans (microfinance): Small loans to people who can't get regular bank credit, often women starting small businesses. Muhammad Yunus and the Grameen Bank in Bangladesh won the 2006 Nobel Peace Prize for the idea; studies show mixed results on reducing poverty.
Rostow's stages of economic growth (1960): Every country moves through five stages: traditional society, preconditions for take-off, take-off, drive to maturity and high mass consumption.
Limits of Rostow: Based on Western history, it assumes every country follows one path and ignores outside forces like colonialism, global trade rules and debt. It also assumes high mass consumption is the goal, ignoring environmental limits.
World-system theory (Immanuel Wallerstein, 1974): The world is one unequal capitalist economy of core, semi-periphery and periphery countries. The core gains from the periphery's cheap labor and raw materials, and countries can move between tiers.
Core, semi-periphery and periphery: Core: wealthy, high-tech, high-wage countries such as the U.S., Western European countries and Japan. Semi-periphery: industrializing countries such as China, India, Brazil and Mexico, both exploited and exploiting. Periphery: lower-income countries relying on raw materials and cheap labor.
Dependency theory: Poorer countries stay poor because colonialism and unequal trade locked them into exporting cheap raw materials to richer countries. It explains inequality well but struggles with East Asian countries like South Korea that grew rich through trade.
Commodity dependence: Relying on exporting one or a few raw goods, such as Zambia with copper or Nigeria with oil. When world prices fall, the whole economy suffers.
Limits of world-system and dependency theories: They describe inequality well but are weaker at predicting change, focus mostly on economics, and lump very different countries into broad groups.
Weber's least cost theory (Alfred Weber, 1909): Factories locate where costs are lowest, mainly transportation and labor, plus savings from agglomeration. Bulk-reducing industries, like copper smelting, locate near raw materials; bulk-gaining ones, like soft-drink bottling, locate near markets.
Limits of Weber: It assumes one market, fixed raw-material sites and equal conditions elsewhere. It underplays cheap container shipping, government incentives, the skilled workforce and the fact that many firms aren't trying to cut every cost.
Agglomeration: Related firms clustering together to share workers, suppliers and ideas, such as tech in Silicon Valley.
Break-of-bulk point: A place where goods switch from one kind of transport to another, such as from ship to rail or truck at a port like Rotterdam or Singapore. Shipping containers made these transfers fast and cheap.

Trade, globalization and sustainable development

Unit 7

Complementarity: One place has what another needs and vice versa, so they trade.
Comparative advantage: Each place should make what it gives up the least to produce and trade for the rest. Both sides can gain even if one is better at making everything.
Neoliberalism: Policies of free trade, privatization and fewer regulations that spread from the 1980s. Supporters credit them with growth; critics link them to debt crises and painful spending cuts in some countries.
World Trade Organization (WTO): Set up in 1995 to make and enforce rules for trade between countries and lower trade barriers.
International Monetary Fund (IMF) and World Bank: Created in 1944. The IMF lends to countries in financial crisis; the World Bank funds development projects. Their loans have often come with conditions, called structural adjustment, that required cuts and market reforms. Debt crises show how tightly the world's economies are linked.
Trade blocs and agreements: Groups of countries that lower trade barriers among themselves: the EU, USMCA (the United States, Mexico and Canada, which replaced NAFTA in 2020), Mercosur in South America and ASEAN in Southeast Asia.
OPEC: Founded in 1960, a group of oil-exporting countries that coordinates oil production to influence prices.
Tariffs and government initiatives: A tariff is a tax on imports. Governments at every scale use tariffs, subsidies, tax breaks and trade deals to protect or attract industries, which shapes where jobs and factories go.
Outsourcing and offshoring: Outsourcing is hiring another company to do part of the work; offshoring is moving work to another country, usually to cut labor costs.
Deindustrialization: The loss of manufacturing jobs in older industrial regions, such as the U.S. Rust Belt, as factories close or move to lower-cost places.
Newly industrialized countries (NICs): Countries that industrialized quickly through export manufacturing, such as South Korea, Taiwan, Singapore and Hong Kong (the "Asian Tigers"), and later China.
Special economic zones, free-trade zones and export-processing zones: Areas with low taxes and fewer rules to attract foreign companies and exports, such as Shenzhen, China (1980). Free-trade zones work similarly. Mexico's maquiladoras near the U.S. border are factories that assemble imported parts for export. These zones are part of an international division of labor in which lower-paid manufacturing jobs move to developing countries.
Fordism vs. post-Fordism: Fordism is mass production of standard goods on assembly lines. Post-Fordism is flexible production of smaller batches, spread across many places and suppliers.
Just-in-time delivery: Parts arrive right when they're needed, so companies hold little inventory. It saves money but makes supply chains fragile when shipping is disrupted.
Growth pole and multiplier effect: A growth pole is a cluster of businesses that drives growth in the surrounding region. The multiplier effect is how new jobs create more jobs, as workers spend money at local businesses.
Global supply chain: The network of places that design, source, make, ship and sell a product. A phone or shirt may pass through many countries.
Sustainable development: Development that meets today's needs without harming future generations' ability to meet theirs, a definition from the UN's 1987 Brundtland Report.
UN Sustainable Development Goals (SDGs): 17 goals adopted in 2015 with a 2030 target, covering poverty, hunger, health, education, gender equality, clean water, clean energy, climate and more.
Ecotourism: Tourism built around nature that aims to protect it and benefit local people, as in Costa Rica. It can fund conservation but also bring crowds and damage.
Resource depletion and climate change: Mass consumption, fossil fuel use and water use strain resources and warm the climate, and the costs often fall hardest on lower-income places.