Unit 3 · Topic 3.9 Beta

Demographic Transition

The demographic transition model follows a country’s crude birth and death rates as it develops.

Practice 2: Visual RepresentationsPractice 5: Data Analysis

Part 1 · Hook

Why this matters

Two hundred years ago, nearly every country had high birth rates and high death rates, and populations grew slowly. Then, one country after another, death rates fell, populations boomed, and later birth rates fell too. The pattern has repeated so often, from England to Mexico to South Korea, that geographers drew it as a model: the demographic transition.

Part 2 · Before you start

What this builds on

Part 3 · Prerequisite check

Quick check before you start

1. A country has a crude birth rate of 30 and a crude death rate of 10. What is its rate of natural increase?

  1. 2%
  2. 20%
  3. 0.2%
  4. 3%
Show the answer

(30 - 10) / 10 = 2% a year.

  • Correct: 2%:
  • 20%:
  • 0.2%:
  • 3%:

2. Which change tends to lower a country’s total fertility rate?

  1. More schooling for girls and women
  2. Earlier marriage
  3. Higher infant mortality
  4. Children working on family farms
Show the answer

Schooling delays marriage and widens choices, so families have fewer children.

  • Correct: More schooling for girls and women:
  • Earlier marriage:
  • Higher infant mortality:
  • Children working on family farms:

Part 4 · See it

See it first

Demographic transition model in four stages. Stage 1 preindustrial: crude birth and death rates both near 40 per 1,000, little growth. Stage 2 transitional: the death rate falls to about 12 while the birth rate stays near 40, so the gap (natural increase, shaded) is widest. Stage 3 industrial: the birth rate falls from about 32 to 12 and the gap narrows. Stage 4 postindustrial: both rates low, about 11 and 10, little growth.
The demographic transition model: crude birth and death rates through four stages. The shaded gap between them is natural increase. LevlPrep original diagram.

Part 5 · Step by step

How it works, step by step

  1. Stage 1: little medicine, unsafe water and unreliable foodbirth and death rates are both high, so the population grows slowly
  2. Stage 2: clean water, vaccines and steadier food arrivethe death rate falls fast while the birth rate stays high, so the population grows rapidly
  3. Stage 3: people move to cities, girls go to school, infant mortality is low and family planning spreadsthe birth rate falls, the gap narrows and growth slows
  4. Stage 4: birth and death rates are both lowthe population grows slowly, holds steady, or may start to shrink if births fall below deaths

Part 6 · Key ideas

Key ideas

  • The demographic transition model describes how a country’s crude birth and death rates change as it develops economically, in four stages.
  • Preindustrial stage (1): high birth and death rates, slow growth. Transitional stage (2): death rate falls, birth rate stays high, fastest growth.
  • Industrial stage (3): birth rate falls toward the death rate, growth slows. Postindustrial stage (4): both low, little or no growth, sometimes decline.
  • Each stage has a typical age structure: a wide base in stages 1 and 2, a narrowing base in stage 3, and a column or a narrow base in stage 4.

Part 7 · Misconception

A common mistake

The wrong idea: Populations grow fastest in stage 1, because the birth rate is highest then.

What actually happens: Growth depends on the gap between births and deaths. In stage 1 both are high, so the gap is small. Growth is fastest in stage 2, when deaths have fallen but births have not.

Part 8 · Check yourself

Check yourself

Exam-style questions. Anything you miss goes into your review queue.

Model or diagram

The demographic transition model

Demographic transition model in four stages. Stage 1 preindustrial: crude birth and death rates both near 40 per 1,000, little growth. Stage 2 transitional: the death rate falls to about 12 while the birth rate stays near 40, so the gap (natural increase, shaded) is widest. Stage 3 industrial: the birth rate falls from about 32 to 12 and the gap narrows. Stage 4 postindustrial: both rates low, about 11 and 10, little growth.
LevlPrep original diagram.

1. In which stage of the model is the gap between the birth rate and the death rate widest?

  1. Stage 2, transitional
  2. Stage 1, preindustrial
  3. Stage 3, industrial
  4. Stage 4, postindustrial
Show the answer

The widest gap means the fastest natural increase.

  • Correct: Stage 2, transitional: Right: the death rate has fallen but the birth rate is still near 40, so the shaded gap is widest.
  • Stage 1, preindustrial: Both rates are high and close together; growth is slow.
  • Stage 3, industrial: The birth rate is falling, so the gap is narrowing.
  • Stage 4, postindustrial: Both rates are low and close together.

2. According to the model, what change marks the start of stage 3?

  1. The death rate begins to fall
  2. The birth rate begins to fall steeply
  3. Both rates rise together
  4. The death rate rises above the birth rate
Show the answer

Stage 2 is the falling death rate; stage 3 is the falling birth rate.

  • The death rate begins to fall: The death rate falls in stage 2, before stage 3.
  • Correct: The birth rate begins to fall steeply: Right: in stage 3 the birth rate drops toward the death rate.
  • Both rates rise together: Neither rate rises in the model.
  • The death rate rises above the birth rate: That does not happen in stage 3.

3. Which explanation best accounts for the falling death rate in stage 2?

  1. Women having fewer children
  2. More people moving to other countries
  3. Clean water, vaccines and more reliable food
  4. An older population with many more retirees
Show the answer

Death rates fall first because public health spreads faster than changes in family size.

  • Women having fewer children: That lowers the birth rate, which happens later, in stage 3.
  • More people moving to other countries: Migration does not change the crude death rate in the model.
  • Correct: Clean water, vaccines and more reliable food: Right: these cut deaths from disease and hunger, especially among children.
  • An older population with many more retirees: An older population would raise the death rate, not lower it.

Data

One country over 150 years

Crude birth and death rates, per 1,000 people per year, in one country (invented data for practice)
YearCrude birth rateCrude death rate
18703834
19103720
19503012
1980179
20201010

4. In the table, between which two years did the country’s death rate fall the most?

  1. 1910 and 1950
  2. 1950 and 1980
  3. 1980 and 2020
  4. 1870 and 1910
Show the answer

Subtract each pair of death rates and compare.

  • 1910 and 1950: From 20 to 12 is a drop of 8.
  • 1950 and 1980: From 12 to 9 is a drop of 3.
  • 1980 and 2020: From 9 to 10 is a small rise.
  • Correct: 1870 and 1910: Right: from 34 to 20, a drop of 14 per 1,000.

5. What was the country’s rate of natural increase in 1910, in percent?

Type a number, then its unit (%). Scale words (2.5 million) and powers of ten (2.5 × 10^6) are read.

Show the answer

37−2010=1.7%\frac{37 - 20}{10} = 1.7\% a year.

  • Answer: 1.7 %

6. Which stage of the demographic transition best fits the country in 2020?

  1. Stage 4
  2. Stage 1
  3. Stage 2
  4. Stage 3
Show the answer

Low, equal rates mark stage 4.

  • Correct: Stage 4: Right: both rates are low and equal at 10, so natural increase is zero.
  • Stage 1: Stage 1 has high birth and death rates; these are low.
  • Stage 2: Stage 2 has a high birth rate; 10 is low.
  • Stage 3: In stage 3 the birth rate is still well above the death rate.

7. Which stage of the demographic transition has high birth rates, high death rates and slow population growth?

  1. Transitional
  2. Industrial
  3. Preindustrial
  4. Postindustrial
Show the answer

Preindustrial: high and high.

  • Transitional: In the transitional stage the death rate has fallen, so growth is fast.
  • Industrial: In the industrial stage the birth rate is falling.
  • Correct: Preindustrial: Right: both rates are high, so the gap and the growth are small.
  • Postindustrial: In the postindustrial stage both rates are low.

Part 9 · Summary

Summary

The demographic transition model follows a country’s crude birth and death rates as it develops. In the preindustrial stage both are high and growth is slow; in the transitional stage the death rate falls first, so growth is fastest; in the industrial stage the birth rate falls and growth slows; in the postindustrial stage both are low and the population levels off or declines. Each stage has a typical age structure diagram.

Part 10 · Up next

What comes next

Part 11 · Connections

Connections

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