1.1 Population and economic development patterns

Question 1

Define human development

Answer 1

-The ways in which a country seeks to progress economically and also to improve the quality of life for its inhabitants.

-A country’s level of development is shown firstly by economic indicators of average national wealth and/or income, but can encompass social and political criteria, too.

Question 2

Define scale

Answer 2

-Places, areas, or territories can be studied and identified at a variety of geographic scales, from local territories to the national or state level.

-The global distribution of population is a macroscale (planetary scale) data pattern.

-In contrast, very small-scale patterns are sometimes called microscale distributions.

Question 3

Important features of population distribution

Answer 3

-People are distributed unevenly among the world’s continents. Over half of Earth’s population is in Asia; 1.2 billion people live in Africa and a further billion are spread across North and South America. The figures for Europe and Oceania (Australia and New Zealand) are 740 million and 40 million respectively (2016 data).

-Many people live along coastlines; relatively fewer inhabit the continental interiors. This is one reason why the Lorenz curve for global population distribution looks the way it does.

-Just one-third of Earth’s surface is land and more than two-thirds of this is inhabited by fewer than 20 persons per square kilometer, including (when looking at the national average) Russia, Canada, Australia, Greenland, most of South America, Antarctica, and Saharan Africa.

Question 4

Dot map showing the global distribution of areas where there is a high density of population

Answer 4

Question 5

A Lorenz curve showing the unequal distribution of the world’s population

Answer 5

Question 6

Importance of physical influences on food production- including climate and soil fertility- now and in the past

Answer 6

-Historically, early settlers in any world region lived, either by choice or necessity, wherever the environment provided them with ‘a foothold to livelihood’.

-Even today, around one-third of the world’s economically active population obtains its food and/or income by actively farming the land.

-This means that physical influences on food production – including climate and soil fertility – remain hugely important factors in determining where more than 2 billion of the world’s people live and work.

Question 7

Why are there low levels of population density in continental interiors?

Answer 7

Inaccessibility and extremes of climate (including high daily or annual temperature ranges) mostly discourage large-scale settlement in central areas of Asia and Saharan Africa.

Question 8

Impact of water availability on where people choose to locate

Answer 8

-Historically, fewer people have settled permanently in regions where water availability is lacking for all or part of the year, such as the Sahara and Gobi deserts.

-In contrast, linear distribution of population can be observed following the course of major rivers including the Nile and Amazon.

Question 9

Impact of presence of mountains on where people choose to locate

Answer 9

Population tends to be sparse in mountainous regions such as the Tibetan plateau and American Rockies.

Question 10

How does technology affect the importance of physical factors?

Answer 10

-In the absence of technology, physical factors help establish whether or not a region will become home to a significant human population.

-Over time, however, imbalances between regions may become amplified or lessened on account of human factors.

Question 11

Example of the impact of technology on the importance of physical factors- the USA

Answer 11

-For instance, hot and dry climates may attract large numbers of settlers once sufficient capital and technology are available to provide water supplies artificially.

-Between 2000 and 2010, several states in the USA’s arid southwest experienced rapid population growth rates more than double the national average.

-These were Nevada (35 percent), Arizona (25 percent), and Utah (24 percent).

-This rapid growth has been sustained by pipeline transfers of water from the Colorado River.

Question 12

Example of the impact of technology on the importance of physical factors- the Middle East

Answer 12

-The uneven distribution of mineral deposits and fossil fuels can help explain pockets of prosperity in areas where the population is generally sparse as a result of climatic factors.

-The growth of large urban areas in the Middle East – including Riyadh in Saudi Arabia and Doha in Qatar – has been made possible by the oil wealth, which pays for air conditioning and the desalinization of seawater.

Question 13

Define population distribution

Answer 13

-A description of the way in which people are spread out across the Earth’s surface.

-For instance, around 4.5 billion people live in Asia.

Question 14

Define population density

Answer 14

-The number of people living within a specified area.

-For instance, the population density of large parts of New Mexico (USA) is less than one person per square kilometer.

Question 15

What is the Lorenz curve?

Answer 15

-A diagrammatic expression of the extent to which a distribution is unequal.

-The dashed straight diagonal line on a Lorenz curve shows a perfectly even and equal distribution.

-The further away the solid curved line deviates from this dashed line, the greater the level of inequality that actually exists for the scenario shown.

Question 16

Define arid

Answer 16

A climate whose precipitation is less than 250 mm annually.

Question 17

Define desalinization

Answer 17

-The removal of salt and other minerals from seawater.

-The process is costly and requires desalinization plants to be built.

Question 18

Physical factors affecting large-scale variations in population distribution

Answer 18

-Physical accessibility

-Relief and soils

-Climate

-Vegetation

-Water supply

Question 19

How can physical accessibility lead to a sparse population?

Answer 19

-Rugged mountains (Alps)

-High plateau (Tibet)

Question 20

How can relief and soils lead to a sparse population?

Answer 20

-Frozen soils (Siberia)

-Eroded soils (Sahel)

Question 21

How can climate lead to a sparse population?

Answer 21

-Low temperatures (Canada and Alaska)

Question 22

How can vegetation lead to a sparse population?

Answer 22

Dense forest that restricts human activity (Amazonia)

Question 23

How can water supply lead to a sparse population?

Answer 23

Insufficient or unpredictable supply (Australian desert)

Question 24

How can physical accessibility lead to a dense population?

Answer 24

Flat lowlands (Netherlands, Nile valley)

Question 25

How can relief and soils lead to a dense population?

Answer 25

-Deep humus (Paris basin)

-River silt (Ganges delta)

Question 26

How can climate lead to a dense population?

Answer 26

Longer growing season (tropical Asia)

Question 27

How can vegetation lead to a dense population?

Answer 27

Grassland ecosystems (eastern Europe)

Question 28

Human factors affecting large-scale variations in population distribution

Answer 28

-Economic factors

-Political factors

-Technological factors

Question 29

How can economic factors lead to a sparse population?

Answer 29

Extensive agriculture (few workers needed per unit area)

Question 30

How can political factors lead to a sparse population?

Answer 30

Low levels of state investment (interior of Brazil)

Question 31

How can technological factors lead to a sparse population?

Answer 31

Lack of technology needed to increase water availability

Question 32

How can economic factors lead to a dense population?

Answer 32

-Ports (Singapore)

-Intensive farming (China)

Question 33

How can political factors lead to a dense population?

Answer 33

Forced movements (Soviet settlement of Siberia)

Question 34

How can technological factors lead to a dense population?

Answer 34

Irrigation and desalinization technologies available

Question 35

Interconnection between hazards and resources

Answer 35

-Both are best described as ‘relationships’ between humans and the natural world.

-The only difference is that resources are a ‘positive’ interaction and hazards are a ‘negative’ interaction.

Question 36

Give an example of how many things in the natural world are both a resource and a hazard

Answer 36

-Rivers and coastlines function as sources of water, food, or transport and yet can be incredibly dangerous to live next to.

-Many of the world’s highest-density pockets of population are located in tectonically hazardous areas.

-This is because they have been drawn to coastlines that have formed along continental plate boundaries.

-The Californian coastline is a good example of this: the economic success of Los Angeles and San Francisco owes much to their position on the Pacific coastline.

-However, these are also dangerous places to live on account of the high earthquake risk.

Question 37

Example of how relationships between people and the environment are constantly changing because of technology

Answer 37

-We can build defenses to protect ourselves from river flooding while continuing to make use of its water as a resource.

-Thanks to water transfer schemes, the city of Las Vegas currently prospers in a desert area that was once viewed as a life-threatening environment.

Question 38

‘People are most likely to live where resources are maximized and hazards are minimized.’- factors to consider

Answer 38

-Hazards and resources are interlinked

-Many things found in the natural environment are both a hazard and a resource

-Relationships between people and the environment are constantly changing because of technology

Question 39

Diagram showing how hazards are harmful interactions between humans and the natural world and resources are beneficial interactions

Answer 39

Question 40

Map showing how the world divided crudely into a core of high-income developed countries, a semi-periphery comprised of middle-income countries (or emerging economies), and a periphery of low-income developing countries.

Answer 40

Question 41

Key features of distribution patterns for emerging economies (EEs) and low-income countries (LICs)

Answer 41

-Most South American countries are EEs

-Asia now has more EEs than LICs

-Africa still has more LICs than EEs

-Eastern European countries (including some European Union members, are classified mainly as EEs).

Question 42

In the 1980s, there was still a clear divide between the rich ‘global north’ and the poor ‘global south’. Why does this crude division now seem outdated?

Answer 42

-China has become the world’s largest economy

-Several of the world’s highest-income countries, including Qatar, Kuwait, and Singapore, are part of what used to be called ‘the global south’

-The average income of some European populations, including Hungary and Bulgaria, is lower than that of either Brazil or Malaysia

-Large numbers of millionaires and billionaires can be found in every populated continent, including Africa.

Question 43

What are the three main groups of countries (classified by per capita income and economic structure)?

Answer 43

-Low-income developing countries (LICs) (global periphery)

-Middle-income emerging economies (EEs) (semi-periphery)

-High-income developed countries (HICs) (global core)

Question 44

Characteristics of low-income developing countries (LICs) (global periphery)

Answer 44

-Agriculture still plays an important role in their economies.

-Some of these states suffer from political instability and conflict; some, including Somalia and Eritrea, have been described pejoratively as ‘failed states’ (the term ‘fragile state’ may be preferable to use).

Question 45

Characteristics of middle-income emerging economies (EEs) (semi-periphery)

Answer 45

-These are around 80 countries that have begun to experience higher rates of economic growth, usually due to rapid factory expansion and industrialization.

-They are home to a rising number of the ‘global middle class’ (people with discretionary income they can spend on consumer goods).

Question 46

Why has the number of EEs increased rapidly in recent decades?

Answer 46

This is linked to the spread of globalization and investment by transnational corporations (TNCs) in EEs (leading to economic ‘take-off’ being achieved).

Question 47

Characteristics of high-income developed countries (HICs) (global core)

Answer 47

-Around half are sometimes called ‘developed’ countries.

-These are states where office work has overtaken factory employment, creating a ‘post-industrial’ economy.

-There are also around 40 smaller high-income countries and territories (of roughly one million people or fewer), including Bahrain, Qatar, Liechtenstein, and the Cayman Islands.

Question 48

Define globalization

Answer 48

The variety of accelerating ways in which places and people have become connected with one another as part of a complicated global system.

Question 49

What are transnational corporations (TNCs)?

Answer 49

-Businesses whose operations are spread across the world, operating in many nations as both makers and sellers of goods and services.

-Many of the largest are instantly recognizable ‘global brands’ that bring cultural change to the places where products are consumed.

Question 50

What is gross domestic product (GDP)

Answer 50

-A widely used measurement of national economic wealth that can be used to map spatial variations in economic development.

-It is one of the best-known measures of national and global prosperity used by the World Bank.

Question 51

Define GDP

Answer 51

-A measure of the total value of the output of final goods and services inside a nation’s borders.

-Each country’s annual calculation includes the value added by any foreign-owned businesses that have located operations there. Informal

Question 52

What is the informal sector?

Answer 52

-Unofficial forms of employment that are not easily made subject to government regulation or taxation.

-Sometimes called ‘the black economy’ or ‘cash in hand’ work, informal employment may be the only kind of work that poorly educated people can get.

Question 53

Define purchasing power parity

Answer 53

A measure of average wealth that takes into account the cost of a typical ‘basket of goods’ in a country. In low-income countries, goods often cost less, meaning that wages go further than might be expected in a high-income country.

Question 54

Describe what HDI is

Answer 54

It is a multi-component measure of development that uses life expectancy, adult literacy rates, and GDP to form a score between 0 and 1, 1 being the highest.

Question 55

Why is there an uneven population distribution in all countries?

Answer 55

Because population density varies between local regions.

Question 56

Give an example of a country in which the variety of population density is extreme

Answer 56

95 per cent of Egypt’s people live in the Nile valley (just 4 per cent of the total land area).

Question 57

Give an example of population imbalance in a country

Answer 57

-More than 30 per cent of the UK’s population are in the southeast of England living at a density level of more than 300 persons square kilometre.

-In contrast, just 4 million people inhabit Scotland, despite its much larger area.

-This population imbalance is both caused by, and further creates, a national economic balance.

Question 58

Diagram showing backwash processes in the Friedmann core-periphery model

Answer 58

Question 59

Development of a strong economic core

Answer 59

-A strong economic core develops fuelled by the in-migration of people (workers and investors) from the peripheral regions of a state.

-In economic theory, additional core regions form as part of the development process over time. The growth of these cores is fuelled by flows of raw materials and workers from neighboring areas.

Question 60

Why do regional imbalances in population density arise initially?

Answer 60

-Because of physical factors and the natural advantages of certain locations over others (such as raw material availability or the presence of a coastline).

-Subsequently, these favoured areas become ‘national-scale core’ regions.

Question 61

How do ‘national-scale core’ regions build on their natural advantage through time?

Answer 61

-The attracting force they exert draws in ambitious migrants, investors and resources from other regions.

-This virtuous circle of spiralling growth was called ‘cumulative causation’ by the theorist Gunnar Myrdal.

-The inflows of migrants and resources to the core are called backwash effects.

Question 62

What is the result of cumulative causation?

Answer 62

The development of national core-periphery systems that keep strengthening over time on account of positive feedback effects.

Question 63

Example of how the process of core-periphery polarization can be seen operating at larger spatial scales than the state level

Answer 63

-Within the European Union (EU), free movement of labour has helped an international core-periphery pattern to develop.

-The EU core region encompasses southern England, northern France, Belgium and much of western Germany.

-It includes the world cities of London, Paris, Brussels and Frankfurt.

-Labour migration flows from eastern and southern Europe are directed overwhelmingly towards these places.

Question 64

Much of the voluntary internal migration that takes place within core-periphery systems is directed from ___

Answer 64

Rural to urban areas

Question 65

What causes voluntary internal rural-urban migration that takes place within core-periphery systems?

Answer 65

This is caused by push and pull factors and is encouraged further by the availability of good transport links and communications.

Question 66

Key points about rural-urban migration and urbanization

Answer 66

-In terms of the numbers involved, rural-urban migration is the most significant population movement occurring globally.

-Within a few years, there will be one billion rural-urban migrants living in the world’s towns and cities.

-Global urbanization passed the threshold of 50 percent in 2008, meaning that the majority of people now live in urban areas.

-By 2040, it is expected that over 70 percent of the world’s population will live in towns and cities compared with less than 30 percent in 1950.

Question 67

Define backwash

Answer 67

-Flows of people, investment and resources directed from peripheral to core regions.

-This process is responsible for the polarization of regional prosperity between regions within the same country.

Question 68

Define the core-periphery system

Answer 68

The uneven spatial distribution of national population and wealth between two or more regions of a state or country, resulting from flows of migrants, trade and investment.

Question 69

Define internal migration

Answer 69

-The movement of people from place to place inside the borders of a country.

-Globally, most internal migrants move from rural to urban areas (‘rural–urban’ migrants).

-In the developed world, however, some people move from urban to rural areas too (a process called counterurbanization).

Question 70

Define urbanization

Answer 70

An increase in the proportion of people living in urban areas.

Question 71

Causes of rural-urban migration

Answer 71

-Urban pull factors

-Rural push factors

-‘Shrinking world’ technology

Question 72

Examples of urban pull factors

Answer 72

-Employment

-Schooling

-Healthcare

Question 73

Explain how employment can be an urban pull factor

Answer 73

-Foreign direct investment (FDI) by TNCs in cities of emerging economies provides a range of work opportunities with the companies and their supply chains.

-We can distinguish between formal sector employment (working as a salaried employee of Starbucks in São Paulo, for instance) and the informal sector (people scavenging material for recycling at landfill sites in Lagos).

-Urban areas offer the hope of promotion and advancement into professional roles that are non-existent in rural areas.

Question 74

Explain how schooling and healthcare can be urban pull factors

Answer 74

Schooling and healthcare may be better in urban areas, making cities a good place for young migrants with aspirations for their children.

Question 75

Examples of rural push factors

Answer 75

-Poverty (aggravated by population growth and land reforms)

-Agricultural modernization

-Resource scarcity (which can trigger conflict and migration)

Question 76

Explain how poverty (aggravated by population growth and land reforms) can be a rural push factor

Answer 76

Poverty, aggravated by population growth (not enough jobs for those who need them) and land reforms (unable to prove they own their land, subsistence farmers must often relocate to make room for TNCs and cash crops) can cause people to move to urban areas.

Question 77

Explain how agricultural modernization can be a rural push factor

Answer 77

This reduces the need for rural labour further (including the introduction of farm machinery by global agribusinesses like Cargill).

Question 78

Explain how resource scarcity (which may trigger conflict and migration) can be a rural push factor

Answer 78

Resource scarcity in rural areas with population growth, such as the Darfur region of Sudan, may trigger conflict and migration (people then become classified as refugees and not economic migrants, however).

Question 79

Explain how ‘shrinking world’ technology is a cause of rural-urban migration

Answer 79

-Rural dwellers are gaining knowledge of the outside world and its opportunities.

-The ‘shrinking world’ technologies we associate with globalization all play important roles in fostering rural–urban migration.

-Satellites, television and radio ‘switch on’ people in remote and impoverished rural areas.

Question 80

Example of how ‘shrinking world’ technology is a cause of rural-urban migration

Answer 80

-As people in Africa and Asia begin to use inexpensive mobile devices, knowledge is being shared.

-Successful migrants communicate useful information and advice to new potential migrants. Also, transport improvements, such as South America’s famous Trans-Amazon Highway, have removed intervening obstacles to migration.

Question 81

Diagram showing rural-urban (voluntary internal) migration

Answer 81

Question 82

What is an intervening obstacle?

Answer 82

Barriers to a migrant such as a political border or physical features (deserts, mountains, and rivers).

Question 83

What is a megacity?

Answer 83

A city with 10 million people or more

Question 84

How has the number of megacities changed over time?

Answer 84

In 1970 there were just 3; in 2022 there were 44.

Question 85

What causes megacity growth?

Answer 85

They grow through a combination of rural-urban migration and natural population increase due to large numbers of children being born (on account of the fact that many migrants are young adults of child-rearing age).

Question 86

Give an example of how megacity growth can give rise to marked disparities in terms of how a nation’s population is distributed

Answer 86

Almost one-third of Japan’s 128 million people live in Tokyo and its surrounding metropolitan area.

Question 87

In what types of countries have megacities grown especially rapidly?

Answer 87

Low-income (developing) and middle-income (emerging) countries

Question 88

Explain how megacity growth happens in low-income (developing) and middle-income (emerging) countries

Answer 88

-New growth takes place at the fringes of the city where informal (shanty) housing is built by the incomers.

-Centripetal migration brings people to municipal dumps (Lagos), floodplains (São Paulo), cemeteries (Cairo), and steep, dangerous hill slopes (Rio).

-Over time, informal housing areas may consolidate as expensive and desirable districts.

-Rio’s now-electrified shanty town Rocinha boasts a McDonald’s, hair salons, and health clinics.

Question 89

Explain how megacity growth happens in the developed world

Answer 89

-International migration continues to bring population growth, albeit far more slowly, to megacities in the developed world (for example, eastern Europeans moving to greater London, or Mexicans to Los Angeles).

-There is residual internal migration taking place in developed countries too, for instance from the rural heartlands of the USA to New York.

Question 90

Case studies for 1.1

Answer 90

-Uneven population distribution in the USA

-Uneven population distribution in China

Question 91

Give an overview of the population distribution in the USA

Answer 91

-Overall, the USA has a low average population density of 33 persons per square kilometer.

-The figure varies greatly from place to place within the USA, however.

-High densities are found along the eastern coast, especially in the cities of New York, Philadelphia, and Baltimore.

Question 92

Why are high population densities found along the East coast of the USA (e.g. in the cities of New York, Philadelphia, and Baltimore)?

Answer 92

-This is, in part, a legacy of the way Europeans founded new settlements along the eastern seaboard in the 1600s and 1700s.

-Subsequently, economic activity has remained focused on the eastern coastline and the opportunities for trade it brings.

Question 93

How did the movement of European settlers affect population density in the USA?

Answer 93

-Over time, early European settlers moved westwards, often displacing the indigenous populations of each territory they entered.

-Large clusters of the population developed historically around the Great Lakes in cities such as Detroit and Chicago.

Question 94

What areas of the US have low population densities and why?

Answer 94

-Much of the interior of the USA has a low density of fewer than 20 people per square kilometer.

-In many areas west of the Rocky Mountains, the figure is less than one person per square kilometer.

-This reflects the aridity of the Western Desert, including large parts of Texas, New Mexico, Nevada, and Arizona.

Question 95

Why have cities in the interior of the USA with high aridity (Western Desert) gained population in recent decades?

Answer 95

-Due to irrigation and water transfer schemes.

-Much of the area remains devoid of settlement and population though.

Question 96

What is an indigenous population?

Answer 96

An ethnic group that has occupied the place where it lives and calls home for hundreds or thousands of years without interruption.

Question 97

Population density on the west coast of the USA

Answer 97

The west coast – from San Diego as far north as Seattle – is more densely populated, especially the conurbations surrounding the major cities of Los Angeles and San Francisco.

Question 98

Reasons for the high population density on the west coast of the USA

Answer 98

-Many migrants were attracted here on account of its hot, dry climate and the opportunities provided by the Pacific coastline for trade with Asia.

-Los Angeles has become a global entertainment industry hub, which is home to Hollywood.

Question 99

What type of settlement pattern is the USA sometimes said to display?

Answer 99

A ‘binary’ settlement pattern: the world cities of New York and Los Angeles are equally powerful magnets for migrants and investors alike.

Question 100

Map showing the uneven population distribution of the USA

Answer 100

Question 101

What is the population of China?

Answer 101

Around 1.4 billion people

Question 102

Similarities between population distributions in China and the USA

Answer 102

The highest concentrations of people are found along China’s east coast.

Question 103

Where is population density the highest in China?

Answer 103

-The highest concentrations of people are found along China’s east coast.

-Density reaches a maximum in the province of Jiangsu, which is home to many of the world’s leading exporters of electronic equipment and has been China’s largest recipient of foreign investment over many years.

Question 104

Population density in the south of China

Answer 104

-Further south, an urban mega-region of 120 million people has grown around the Pearl River Delta.

-It includes the conjoined cities of Shenzhen, Dongguan, and Guangzhou.

-Hong Kong and Macao also form part of this region.

Question 105

Reasons for the population density in Hong Kong and Macao

Answer 105

Although both territories have been returned to China, they were formerly under British and Portuguese control, respectively, and have long been important trade hubs where many people have wanted to live.

Question 106

Population density in the west of China

Answer 106

Population density falls markedly towards the west in China.

Question 107

Human reasons for the low population density in the west of China

Answer 107

The reduced potential for international trade with distance from the coastline

Question 108

Physical reasons for the low population density in the west of China

Answer 108

-Parts of China’s interior are extreme environments.

-The Tibetan plateau is a high-altitude region covering 2.5 million square kilometers, where temperatures fall as low as –40ºC in the winter months.

-The Gobi desert is a vast, sparsely populated area that overlaps part of northern China.

Question 109

How has population distribution changed in China in the last 40 years?

Answer 109

-Major population relocations have taken place, which has reduced the population density of some provinces while increasing the density of others markedly.

-China’s total population has not grown very rapidly on account of (until recently) strict political controls limiting the number of births.

-Therefore, population changes in most regions are largely attributable to migration.

Question 110

Political influences on migration in China

Answer 110

-Since 1978, when political and economic reforms began in China, more than 300 million people have left rural areas in search of a better life in cities.

-Only a strict registration system called hukou has prevented rural villages from emptying altogether. During this time, the percentage of China’s population living in cities has risen from 20 to nearly 60 percent.

-Between 1990 and 2010, the population of Guangdong province in the Pearl River Delta grew from 62 million to 104 million: a phenomenal rise over a 20-year period.

Question 111

Choropleth map showing the uneven distribution in China

Answer 111

Question 112

Uneven population distribution in Australia- physical and human factors

Answer 112

Physical:

-Coastal areas are densely populated, with the highest clusters of population in the south-east and the east (e.g. states like Victoria).

-The Northern Territory is a state with a low population. Its climate ranges from tropical in the north and arid in the south. Desert-like conditions exist in the center.

-More-populated areas, such as Victoria, experience a temperate climate. Temperatures range from 6 to 25 degrees C.

Human:

-Primary industries are also important and attract migration. For example, mining has boosted the GDP of Queensland and Western Australia.

-The growth of tertiary industries in eastern and south-eastern cities has attracted internal and external migrants.

Question 113

Uneven population distribution in Kenya- physical and human factors

Answer 113

Physical factors:

-Areas of fertile soil (such as the highlands of the Rift Valley) enable higher agricultural yields.

-Arid climate conditions in the north-east have caused drought and famine in the past

Human factors:

-Domestic and foreign investment in a “northern corridor” have encouraged internal migration.