Population change 1 What is demographic change?

1.1 What is demographic change? The net change in the population store caused by the inputs of births and in-migration and the outputs of death and out-migration. Global population growth, totals, distribution and density How and why do populations change naturally? A study of countries at Stages 2-5 of the demographic transition to demonstrate variations in fertility and mortality rates, including infant mortality and life expectancy. 1.3 What is the role of migration in population change? Characteristics of different types of migration. The economic, social and environmental impacts of migration on exporting and receiving countries/regions. 1.4 What are the issues of the migration of refugees and asylum seekers? The causes and consequences of flows of refugees and asylum seekers into developed economies both from a historical and current dimension. Housing. Repatriation. The attitudes and values of migrants and hosts. Human rights.

1.5 What are the causes and impacts of changing gender structures? Changing gender structures in populations as countries pass through the demographic transition. Social, economic and political impacts of gender structures. 1.6 What are the demographic challenges facing countries? The demographic causes and effects of ageing societies including issues such as dependency, workforce and pensions. The issues of high birth rates and high mortality rates – including AIDS. Policies to alleviate the ‘demographic challenges’

Population Change Births Immigrants Deaths Emigrants Total Population Natural Increase Migration The total population of an area is the balance between 2 forces of change: natural increase and migration Natural increase is the balance between birth rates and death rates, or in other words between fertility and mortality, Inputs Outputs

Fertility There are a number of measures of measuring fertility. Crude birth rate (the most common measure of fertility) CBR = total number of births X 1000 total population But it doesn’t consider the age and sex distribution of the population. Age-specific fertility rate. This is a measure of the number of children born to each age group in relation to the number of women in each age group. Usually 7 age groups are used from 15 to 49 years old. ASFRs are normally expressed per 1000 women in each age group. From ‘Population,Resources and Development ‘(2 nd ed.) J Chrispin and F Jegede Collins Educational

Replacement level fertility is the level at which each generation of women has only enough daughters to replace themselves in the population. These levels vary for different populations, depending on mortality rates and the sex composition of the population. Usually a replacement level of 2.12 children is considered as replacement level. Mortality prevents a proportion of the female population from reaching their productive years, and also, on average, slightly more boys than girls are born. Replacement level fertility rates have been falling steadily over the world over the last 50 years.

Mortality The Crude Death rate is calculated by the number of deaths per 1000 population in one year. CDR = total number of deaths X 1000 total population The CDR is heavily influenced by the age structure of the population. A developed country with more older people might have a similar CDR to a developing country with much higher infant mortality rates and a lower life expectancy. Age-specific death rate =number of deaths in a specified age group x 1000 population of the age group The age specific death rate of 0-5 year olds is generally referred to as child mortality. Infant mortality is the number of deaths before a child’s first birthday, and is a good indication of the state of health care in a country.

Infant mortality rates per 1000

Number of years to add each billion (year) All of Human History (1800) 130 (1930) 30 (1960) 15 (1975) 12 (1987) 12 (1999) 14 (2013) 14 (2027) 21 (2048) Sources: First and second billion: Population Reference Bureau. Third through ninth billion: United Nations, World Population Prospects: The 2004 Revision (medium scenario), World Population Growth, in Billions

Millions Annual Increase in World Population Source: United Nations, World Population Prospects: The 2004 Revision, 2005.

Billions Less Developed Regions More Developed Regions Source: United Nations, World Population Prospects: The 2004 Revision (medium scenario), Growth in More, Less Developed Countries

Trends in Population Growth Worldwide Population Increase and Growth Rate, Five-Year Periods Millions Percent increase per year Source: United Nations, World Population Prospects: The 2004 Revision (medium scenario), 2005.

Notes on Trends in Population Growth Worldwide This figure illustrates the lag between changes in the rate of growth and the net increase in population per year. Over the period , the population growth rate declined (a reflection of declining fertility), yet millions of people were added to the world’s population (which peaked around 1985, when 87 million people were added each year). From 2000 on, the growth rate will continue to decline. Between 2015 and 2020, we will still be adding 72 million people each year. Why? Because the generation of women now having their children is very large as the result of high fertility in their mothers’ and grandmothers’ generations.

World Population Clock Natural Increase perWorld More Developed Countries Less Developed Countries Less Developed Countries (less China) Year80,794,2181,234,90779,559,31171,906,587 Day221,3543,383217,971197,004 Minute Source: Population Reference Bureau, 2005 World Population Data Sheet.

Projected Population Change, by Country Percent Population Change, All of the most recent projections put forth by the UN assume that levels of childbearing will continue to decline in the next century. Women worldwide are having fewer children in their lifetimes, from an average of five children born per woman in the 1950s to below three in 2000.

Global Natural Increase

Doubling Time This map shows how long it will take for countries to double their population if it continued to grow at the present rate

Population densities

Life expectancies 2000 and 2025

Life expectancy

Life Expectancy at Birth, in Years Source: United Nations, World Population Prospects: The 2004 Revision (medium scenario), Trends in Life Expectancy, by Region

© 2006 Population Reference Bureau In , infants born around the world can expect to live an average of 75 years — up ten years from today. Africa will experience the largest increase in life expectancy: from 49 years to 65 years. Life expectancy varies widely by region. In more developed countries, life expectancy averages 76 years, compared with only 49 years in Africa. Notes on Trends in Life Expectancy, by Region