Population structure

• Population pyramid: Population structure is best illustrated by a population or age-gender pyramid.
• Population pyramid: It divides the population into 5-year age groups (0-4, 5-9, 10-14…) on the vertical scale and into males and females on the horizontal scale.
• Population pyramid: The numbers are given in percentage of the total population.
• Population pyramid: The pyramid shows the effects of migration, age and gender of migrants and the effects of large-scale wars and major epidemics of disease.
• Population pyramid: A triangular shape indicates that there are more young people than old people, while an upside down triangle means that there are many elderly people compared to younger ones.
• Population pyramid: If the number of men and women is equal at all ages, then the pyramid will be symmetrical with respect to the central axis.
• Population pyramid: If the two sides of the pyramid have similar shapes, it suggests that both sexes experience similar mortality rates at all ages.
• Population pyramid: The pyramid has 4 basic types. Expansive = Niger, Expansive = Bangladesh, Stationary = UK, Contractive = Japan.
• Contractive type - low birth rate and high death rate
• Stationary type - low birth rate and death rate
• Expansive type - high birth rate and low death rate
• Demographic transition model (DTM) - describes how population growth changes over time as societies develop economically and socially
• Dependency ratio: Relationship between the working or economically active population and the nonworking population.
• Ageing populations are more likely to have higher dependency ratios than younger ones because there is a greater proportion of people who cannot work due to being too young or old.
• Dependency ratio: Calculation: Dependent (0-14 + >65 = dependent) age groups divided by age groups between 15 to 64 (active number) times 100 = dependency ratio.
• Population policies: It encompasses all of the measures taken by a government aimed at influencing population size, growth, distribution or composition.
• Population policies: These policies can promote large families (pro-natalist policies) or encourage fewer births (anti-natalist policies). Most countries that have tried to control fertility have sought to curtail it.
• population policies: In 1952, India became the first developing country to introduce a policy designed to reduce fertility and to aid development with a governmentbacked family planning program. → it was seen to be working, so other developing nations followed India
• Population policies in China: Most severe family planning program. In the aftermath of the communist revolution in 1949, population growth was encouraged for economic, military and strategic reasons.
• Population policies in China: Sterilisation and abortion were banned and families received a benefit payment for every child. 1954 was the population at 600 million and government was worried, so they invented the first birth control program in 1956.
• Population policies in China: “Great Leap Forward” began in 1958 → rapid industrialization + modernization = births were again encouraged. 1964 = new phase of birth control
• Population policies in China: “Late, sparse, few”. 1979 was the one-child policy imposed. It was most effective in urban areas (less wanting a son). In the rural areas they needed/wanted a son so the policy was relaxed so that couples could have two children without penalties.
• Consequences of China policies: Impact on the gender ratio: 119 boys to 100 girls = causing social problems. The reason for this gap is selective abortion after pre-natal screening. The lifespan for a girl is sharply curtailed by infanticide or deliberate neglect.
• Consequences of China policies: 32 million more men aged under 20 than women. → is greatest in rural areas because women are “marrying out” into cities.
• Consequences of China policies: Four-two-one problem → one adult child is left with having to provide support for his two parents and four grandparents.
• Consequences of China policies: Birth rate in 2020: 12/1000 → country’s ageing population = major concern
• Consequences of China policies: 2015 weakening of the rules → allow all couples to have two children from March 2016
• Migration: Movement of people across a specified boundary, national or international, to establish a new permanent (more than 1 year) place of residence.
• Push-factors: Negative conditions at the point or origin that encourage or force people to move. (Intolerance, adverse climatic/ecological conditions, natural disasters, high level of unemployment, bad education, bad health care system, dictatorship)
• Pull-factors: Positive conditions at the point of destination that encourage people to migrate. (Good job projects, higher wages, improved housing)
• Types of migration: Immigration laws present the greatest obstacle to most potential international migrants. In the past the greatest obstacle was the physical danger on the journey. The costs were higher in the past. Countries now attempt to manage immigration carefully → attract people whose skills are in demand.
• Voluntary migration: The individual has a free choice about whether to migrate or no
• Involuntary (forced) migration: The individuals are made to move against their will → this may due to human or environmental factors. The biggest forced migration was transport of Africans to the Americas as slaves. Migration can also be forced by natural disasters (volcanic eruptions, floods, drought…) or by environmental catastrophes.
• Global migration trends: Foreign-born populations are rising in both developed and developing countries
• Global migration trends: Migration has become increasingly temporary and circular in nature → because of the growth in the importance of labourrelated migration and international student mobility.
• Global migration trends: Proportion of female migrants was 48 per cent in 2020 → for some countries of origin, women now make up the majority of contract workers
• Global migration trends: Most migrants move from developing to developed countries.
• Global migration trends: Developed countries have reinforced controls → to combat illegal immigration and networks that deal with human trafficking.
• Global migration trends: Spatial impact of migration has spread. Many traditional migration streams have remained strong and there have been new streams developed
• Global Migration trends: From rural to urban areas