Ch. 2 Key Issue 3

Why Is Population Increasing at Different Rates?

Demographic Transition Model• A model of population change where

high birth rates and death rates transition to low birth rates and death rates relative to (along with and due to) advances in medical technology, and economic and social development.

• A model is a simplified, general version of real events in order to facilitate understanding of a process

Demographic Transition Model

• Based on the shifts that Britain experienced– will other countries follow this same pattern?

• Population pyramids are graphical representations of the different stages (KI 3 pt 2)

Stage 1: Low Growth

• HIGH birth rates and death rates= low growth (low NIR)

• First Agricultural Revolution allowed population to swell

• No countries are in stage 1 anymore.

Impact of the Industrial Revolution (19th Cent)

• Second Agricultural Revolution HAD to occur first– People had to be able to leave the farms to go work in

factories– Improved methods and technologies, expanded storage,

less land used– Greater efficiency = Less people needed to work farms

AND the food supply increased• Industrial Rev- 19th

– Sanitation facilities, modern medicine, vaccines– Increased food supply + medicine = extremely lower death

rates– Migration to industrialized cities

Colonization leads to higher growth rates

• When Europe colonized Africa and Asia, they brought medicines and sanitation techniques that helped them increase their population (Ag/Indust Revs)

• By 1950’s fear of overpopulation began when India, Africa and South America’s CDR declined

• Europe and NA population was stabilizing and “others” were increasing– Moving through different stages of the Demographic

Transition– Decreasing birth rates in Europe and NA- why?

Stage 2: High Growth

• Move to stage 2 caused by severely declining death rates + birth rates remain high= lots of growth.– Industrial revolution (MDCs)– Medical revolution (LDCs)

• What role does diffusion play here?

Stage 3: Moderate Growth

• Fertility (TFR) drops, therefore CBR drops= a decrease in growth

• CDR drop as well but not as bad as CBR.• What cultural and economic factors play

a role in the declining birth rate?

Stage 4: Low Growth

• CDR and CBR become the same until NIR = 0 (ZPG)

• Population has swelled in stages 2 and 3.

• How does this stage compare to stage 4?

Stage 5? Decline?

• Could see some countries moving into a new stage 5: decline

• CDR would increase to be greater than CBR

• Russia, Germany, Italy, Japan

Why is it important to know?

• Countries with high population of younger people have different problems than countries with high old population– Aging population in MDCs vs. low life

expectancies in LDCs– Differing dependency ratios

• US- high elderly dependency (over 65) • Africa- high young dependency (under

15)

Quick Write• Explain the 2 differences in the way

countries transition now (Mexico/LDCs) from in the past (Sweden/MDCs).

• See next slide for answer

0

10

20

30

40

50

60

1775 1800 1825 1850 1875 1900 1925 1950 1975 2000

SwedenBirth Rate

Death Rate

MexicoBirth Rate

Death Rate

Births/Deaths per 1,000

1950

Review DTM

• Stage 1• Stage 2• Stage 3• Stage 4 • Stage 5

Population Pyramids

Bar graphs that show us:• Sex ratio- # of men per 100 women• Age distributions• Dependency ratio- under 15, over 65.• CBRs, CDRs, IMRs• Visual representations of the stages of

the Demographic Transition

Population Pyramids

Post War Baby Boom and Declining Birth Rate. Stage?

World Population Pyramid. What stage is the world in?

Countries in the Dem. Tran.–Three examples:

Cape Verde = High growth (Stage 2)Chile = Moderate growth (Stage 3) Denmark = Low growth (Stage 4)

Cape Verde

Wide base, skinny top

Chile

Slimmer base, widening top

Denmark

Slimmed base, widest top

Extremely High Birth and Death Rates. Stage?

Moderate to low Population Growth. Stage?

Skinnier middle-top makes it stage 3. When lower bulge gets older (lives longer/doesn’t die) then it will be in transition to 4. Compare to Japan on next slide.

Post War Baby Boom and Declining Birth Rate. Stage?

Skinnier bottom with wider top makes this a stage 4. The skinnier the bottom gets, the more it is in transition to stage 5, i.e. the more “top heavy” it gets.

Analysis

What can we determine about these countries':• CBRs/IMRs/TFRs?• CDRs?• Life expectancy?• Development levels (MDC/LDC)?• Dependency ratio?• How are all these concepts related?

Very low stage 2, almost reverting to 1

Stage 2

Stage 2 moving toward stage 3

Stage 3 in Transition

Stage 3?- stable/low growth

Stage 5? Aging population, very low CBR

Population Growth and the Dem. Tran.• Population spike of second half of the 20th

century means few countries are in Stages with low population growth right now.

• Most countries are in stages 2 and 3 and only a few will reach stage 4 in near future = increased world population growth

• Problem: In LDCs, CDRs have declined with diffusion of medical technology but CBRs remain high due to cultural and economic reasons. We talked about the past vs. present transitions that countries make (see Quick the Write).

Can the Earth “carry” us?

Carrying capacity- the maximum number of people the environment can support.

PANIC! AHH! WE’RE ALL GOING TO DIE!!!• Fears that the world’s population

was outpacing the food supply/food production• Adding more fields and crops year by

year BUT having 2 or 3 babies per family!

• Thomas Malthus and Neo-Malthusians vs Marxists

Two Viewpoints:• Malthus on overpopulation

– Food grows arithmetically (by adding); population grows geometrically (by multiplying)

–Assumed food production was confined spatially—i.e., limited to the land we have, and you can only eat what is grown in the country• Today, countries w/o arable land can

import most or all of food they need!

Two Viewpoints• Malthus today: Neo-Malthusians

–LDCs have rapid population growth due to medical technology, but NOT wealth; massive amounts of poor people who cannot feed themselves

–Overpopulation stripping world of resources (clean, air, arable, land, fuel), not just food. Civil wars and violence will increase

Two Viewpoints:

Criticism of Malthus:• Pessimistic (negative) viewpoint• Failure to consider technological

innovation –Fertilizers, mechanization, GMO’s

• Didn’t predict impact of globalization–Trade between countries to get what they

need• Overpopulation a regional instead of

global problem?

Two viewpoints• Criticisms

– Friedrich Engels (Marxist/Communist)• World has enough resources to feed population

if shared equally• Under capitalism, workers do not control the

food and do not make enough to pay for it– World is better off with 7 billion = more

consumers and more jobs– Large population = power, more young men

for military

What does the graph show about possible overpopulation? Does it help or hurt Malthus?

Figure 2-25

Controlling Population Growth

• NIR can decline for only two reasons: drop in CBR or increase in CDR–I don’t think we would want to see an

increase in death rate…Unless you’re Malthus

• So, what is the most effective way to decrease CBR?

Two Ways of Reducing CBR1. The country becomes more

economically developed (Stage 4-5).– Children are an economic/cultural burden

in developed cities– IMR would decrease with improved

medicine2. Use of contraceptives

– Faster results– Diffused by MDCs

Problems with Contraceptives• Low status of women keeps them

from having a choice to use• Women regard high number of

children as having high status in society

• Religious opponents• Political reasons- abortions made

illegal

Which method is better?• While contraceptives are a faster

method to reducing CBR’s, it faces more roadblocks (see last slide).

• But economic development will take longer (moving from stages 2 and 3 to 4).

• Therefore, overpopulation could be seen as a regional problem (specific to one country or area), not a global one…yet

How can Gov’ts affect population change?• 3 policy types: Expansive, eugenic, restrictive• Expansive Policies- encourage large families,

raises NIR– Aging and declining countries could institute

these policies– Tax breaks and other monetary measures

• Russia: $10,000 to women who birth 2nd or 3rd child

• Ulyanovsk- National Conception Day (9/12)- Free Car!

• Sweden- racier TV shows at night

How can Govt’s affect population change?

• Eugenic Policies- favors one racial/ethnic group over another– Nazis- Holocaust– US?- pre civil rights treatments of

Blacks/Af Ams– Japan- nearly homogenous (same)

population—strict immigration policies– Discrimination- higher taxes, less land, etc.

How can Govt’s affect population change?• Restrictive policies- reduce the NIR

– Toleration of birth control, prohibit large families

– China- one-child policy (has been relaxed recently)• Parents were penalized for having two-

fines/extra taxes, housing, education• Increased gender selected abortions;

orphaned girls and resulted in a gender imbalanced population (reason they relaxed it)