Lecture 7: Population
What are the causes of high fertility?
-'passion of the sexes' and a lack of birth control measures/ understanding -social norms/ culture e.g. Hutterites- believe in maximum fertility i.e. 10 children per woman -demographic change: a rise in the proportion of women of reproductive age i.e. 15-45 (birth rate can decline if the proportion of older people goes up) -Economic development i.e. individual rationality: in a person's interest to have more children e.g. supplement household earnings, high child mortality rate (more children increases the survival rate), social security: carrying for elderly
What evidence is there of demographic transition in the developing world since the 1950s?
-1950-70: death rates fell, natural increase high -1950-2005: CBR and CDR fell -in all regions of the world, women started having fewer children
What are examples of capital deepening and capital widening?
-Capital is a factor of production that is used to convert raw materials into a manufactured product e.g. machinery -Capital widening: buying more machinery per worker and building a bigger factory (where the size of the labour force is contstant) -Capital deepening: designing a new improved piece of machinery that required a smaller quantity of labour -Capital deepening would lead to economic growth as it leads to a higher rate of return while maintaining the same inputs
How does accumulation affect population?
-Coale and Hoover (1958): anti-natalists/ population pessimists Argue that a reduction in birth rate would increase per capita income: -slowing down labour force growth: this would reduce the amount of investment needed to maintain capital widening (a constant amount of capital per worker/output per worker) and permit more investment to increase capital deepening (increase capital per worker/output per worker) -if the population is smaller, public funds can be diverted away from education and health expenditure and toward physical capital e.g. machinery -slower population growth would reduce the dependency ratio: this would reduce consumption and increase savings
What is meant by population momentum?
-Past decisions about fertility echoe long into the future e.g. a large proportion of today's population are about to enter the most fertile age bracket -even if today's couples only had enough children to replace themselves (2), world population would continue to growth long into the future before eventually levelling off Example each generation dies off after 1,2,3 etc: Generation 1: 2 couples each have four children (12 people in total- above replacement level) Generation 2: The 8 children form 4 couples and each only has 2 children (16 people in total- at replacement level) Generation 3: The 8 children form 4 couples and each only has 2 children (16 people in total- replacement level stabilises) -Although the second generation reached replacement levels of fertility (2 children per couple) population momentum continued and total population increased from 12-16 -Population momentum can work in reverse: if couples fall below the replacement level of fertility, population will decline in the next generation.
Why are population growth projections misleading?
-Projection: if the world population continues to grow at the 2010 level (1.2%) it will reach 11 billion by 2050 and 26 billion by 2100 -Reality: after accelerating for more than 2 centuries, world population growth has been in decline for the last 4 decades -however, it is unkown how quickly transition to low TFR will be or whether there will be a reversal -UN has 3 different projections of world population growth up to 2100
How does population growth relate to development?
-Robert McNamara (former president of the World Bank) warned in 1973 that population growth is the biggest threat to development -However, preceeding presidents have not been as concerned: although the world population is still growing, the rate of growth has slowed -no longer a population explosion -reducing population growth was not included in the Millenium Development Goals (2000)
How does population growth affect economic development?
-Simon Kuznets reported a lack of correlation between population growth and per capita output growth for 40 less developed nationals between the early 1950s and 1964 -this shows that the relationship between high population and GDP per capita (economic growth) is complex; doesnt mean that there is not a systematic effect
Why is the fact that the growth rate in GDP per capita is equal to GDP growth rate minus population growth rate, misleading?
-Statement: For any given GDP growth rate, per capita growth would be faster the slower the population growth rate -Reality: growth in output is not independent of growth in population -population affects the level of GDP, as it determines the size of the labour force, as well as how many people share the GDP (GDP per capita)
How has low fertility in the developing world affected populations in developed countries?
-TFR has dropped below replacement level: women must have at least two children each during child bearing years for population to replace itself -there is a danger of population implosion in countries with low immigration and low TFR e.g. Germany, Japan and Italy: this will lead to low populations and a large elderly population relient on the exisitng labourforce
Why will the world population continue to grow in the next 50 years?
-desire for large families -failure to achieve the desired number of children due to unprotected sex and child mortality: unwanted children -population momentum: e.g. by 2050, India will have overtaken China as the world's most populous nation due to fertility above replacement level and population momentum -China's population growth will be due to population momentum alone -U.S.'s population growth will be due to immigration
How do population growth rates link to population doubling time?
-doubling time drops from 50 years at a growth rate of 1.5% to 28 years at a growth rate of 2.5%
Give a brief history of world population growth:
-for the most part, in the last 13,000 years since the last ice age, population growth has been 0 (annual births=annual deaths) -it took 10,000 years for the world population to reach 1 billion (1820) -the next billion were added in 110 years (1930) -in the last 4 decades, the world has added 1 billion people every 12 to 15 years -world population reached 7 billion in 2011: 5.8 billion of which live in low and middle income countries -the majority of population growth since the 1950s had taken place in the developing world -1945-2009: world population growth= 1.6% (20 times faster than 0.08% between 1C.E. and 1800)
Why has the rate of natural increase been higher in developing countries?
-higher birth rates: earlier age of marriage -death rates declined more rapidly and at lower income levels (compared to demographic transition in global north): transfer of public health interventions e.g. vaccines, improved water and sanitation -the world population will continue to grow in the next 50 years due to: desire for large families, failure to achieve desired number of children and population momentum
What are the historical causes of population growth?
-introduction of settled agriculture: increased the earth's capacity to sustain life -in the years leading up to the Industrial Revolution, the world's food supply increased and became more reliable -the death rate also fell, life expectancy increased -however there were still intervals of mass death e.g. famine, black death 1300s -Industrial revolution expanded earth's population carrying capacity: innovations in agriculture allowed workers to be transfered to industry while maintaining sufficient food production -also led to fall in food prices -transcontinental railroads, ocean shipping- boosted world food supply: allowed food to be transported to areas of famine/ food deficit quickly -decreased the frequency/ severity of famines -modern medicine, sanitation, pharmacutical production -post WW2: innovation in global north spread to global south -post 1945: population explosion due to better disease control and expansion of world food supply (reduced death rates)
What were the limits to Malthuses theory?
-lived in the early days of the industrial revolution: therefore believed that natural increase would rise as the death rate declined due to economic development i.e. increased wealth and food supplies -didnt forsee a decline in fertility in the 19th Century -contrary to his belief, wages increased dramatically: capital accumulation and technical change offset any tendency for the marginal product of labour to decline i.e. change in labour input creates a change in output if all other factors are constant -other factors did not remain constant -death rates fell due to better nutrition, living conditions and medicine
What is the global pattern of demographic transition?
-most European countries have reached stage 4 -some e.g. Italy and Germany has exceeded stage 4 and have experienced negative population growth: high death rates due to aging populations and low birth rates -population growth due to immigration -low-middle income countries e.g. Jordan, Pakistan, Madagascar etc maintain high growth rates (1-2%) -Sub-Saharan Africa has the highest growth rate -only 16% of the world's population live in high income countries -majority of the world'd population live in East and South Asia
What is demographic transition?
-the transition from high birth and death rates to low birth and death rates Stage 1: high b and d (population increase is 0) Stage 2: d decline quicker than b Stage 3: d declines further and b declines Stage low b and d
What are the costs of having children?
Explicit: cost of food, clothing, education, shelter etc Implicit: opportunity costs of the mother, division of inherited land (large number of children), prioritising education due to limited income (mostly for boys)
What is natural increase?
The difference between CBR and CDR in the population -expressed as a percentage of the population -for the world: natural increase is equal to the world population growth rate -for an individual country: population growth is the difference between natural increase and net migration
What is Total Fertility Rates (TFR)?
The number of children the average woman would have in her lifetime if age specific fertility rates remained constant -sums the age specific fertility rates of women in a given year -TFR can change if women delay having children and if women have fewer children overall
What is crude death rate?
The number of deaths per year per 1000 people
What is crude birth rate?
The number of live births per year per 1000 people
How does economic development affect population growth?
Thomas Malthus- population pessimist: 'Essay on the Principles of Population' -'passion between the sexes' would cause population to expand as long as the world's food supply permitted -Temporary: if wages rose above the subsistence level, people would marry younger and have more children and more would survive -Long term: rise in population would increase labour surply- pussing against fixed land resources -diminishing returns (point where the amount of gain falls below the amount of input) due to the limited carrying capacity e.g. amount of natural resources - leads to a rise in food prices and a decline in real wages back to subsistence level -didnt believe that world food surply would grow faster than world population -this would eventually lead to 'positive checks' relating to death rate e.g. famine, war and disease -'preventative checks' later proposed e.g. later age of marriage (didnt advocate birth control)
What is opportunity cost?
the benefit that a person could have received, but gave up, to take another course of action In the case of women: -as their wages increase, income also increases leading to increased demand for conventional goods and services and presumably children. -however, as market wages increase, opportunity cost of her time also increases so the price of children also rises -the demand for time intensive activities e.g. raising children declines -therefore couples with higher incomes often decide to have fewer children and to invest in higher quality children e.g. spend more time and money on a smaller quantity of children -this describes 'average tendencies'