The Age-Sex pyramid of which countries has a narrow base and tapered top?
Japan
Understanding Age-Sex Pyramids
An Age-Sex pyramid is a graphical representation that shows the distribution of various age groups in a population, which is typically divided into males and females. This visual tool helps demographers and social scientists understand the structure of a population and predict future population trends, such as growth or decline, birth rates, death rates, and life expectancy.
The shape of an Age-Sex pyramid provides clues about the demographic history and future of a country. Different shapes correspond to different population dynamics:
- Expansive Pyramid: Wide at the base and rapidly tapering upwards. This shape indicates high birth rates, high death rates, and a relatively young population with lower life expectancy. It is characteristic of many developing countries.
- Constrictive Pyramid: Narrow at the base, wider in the middle, and tapering towards the top. This shape indicates low birth rates, a smaller proportion of young people, and a larger proportion of middle-aged and older people. It often suggests low death rates and longer life expectancy, pointing towards an aging population and potential future population decline.
- Stationary Pyramid: More rectangular in shape, with the base not significantly wider than the middle sections, gradually tapering at older ages. This shape indicates low birth rates and low death rates, resulting in slow or stable population growth and a higher proportion of middle-aged people.
Analyzing the Narrow Base and Tapered Top Shape
The question asks about a country whose Age-Sex pyramid has a narrow base and a tapered top.
- A narrow base signifies a low birth rate, meaning fewer babies are being born each year relative to the existing population. This leads to a smaller proportion of young people in the population structure.
- A tapered top indicates that the number of people decreases significantly in the older age groups, which can be due to factors like mortality rates or emigration. However, when combined with a narrow base in a developed country, the taper might refer to the natural decline at very advanced ages, but the overall shape is dominated by the small base.
This specific combination of a narrow base and a tapered top most closely describes a population with low fertility rates and potentially varying mortality rates across ages, but fundamentally it's the low number of young people that defines the base.
Examining the Options
Let's consider the general demographic profiles of the given countries:
| Country | Typical Demographic Profile | Likely Pyramid Shape | Narrow Base? |
|---|---|---|---|
| Mexico | Middle-income country, birth rates have declined but are still moderate compared to highly developed nations. Population growth is still positive. | Moving from expansive towards stationary. Base is likely moderately wide, not very narrow. | No (moderately wide) |
| Japan | Highly developed country with one of the lowest birth rates in the world and high life expectancy. Facing significant population aging and decline. | Constrictive. Base is distinctly narrow due to low birth rates. Middle and upper sections are larger proportionally than the base. The top tapers as people reach very old ages. | Yes (distinctly narrow) |
| Nigeria | Developing country with high birth rates and relatively lower life expectancy compared to developed nations. Rapid population growth. | Expansive. Base is very wide due to high birth rates. Tapers rapidly upwards due to higher mortality rates. | No (very wide) |
| Bangladesh | Developing country with high birth rates, though they have declined over time. Still has positive population growth and a large young population. | Expansive. Base is wide due to high birth rates, though possibly less wide than Nigeria. Tapers upwards. | No (wide) |
Based on this analysis, Japan is the country among the options that is well-known for having a very low birth rate, resulting in a characteristically narrow base in its Age-Sex pyramid. While Japan has high life expectancy (leading to a relatively large older population compared to countries with low life expectancy), the fundamental shape driven by low fertility is the narrow base. The top, while containing many elderly people, still tapers towards the very end of the age spectrum.
The description "narrow base and tapered top" fits the general pattern of an aging population with low birth rates, best exemplified by Japan among the choices provided.
Conclusion
The Age-Sex pyramid shape with a narrow base indicates a low birth rate. Among the given countries, Japan has a very low birth rate, leading to a narrow base in its population pyramid. This shape is characteristic of countries with aging populations.
The Age-Sex pyramid of Japan has a narrow base and a tapered top.
Revision Table: Age-Sex Pyramid Shapes
| Pyramid Shape | Base Width | Top Shape | Key Characteristics | Example (Typical) |
|---|---|---|---|---|
| Expansive | Wide | Tapered rapidly | High birth rate, High death rate, Young population, Rapid growth | Nigeria, Bangladesh |
| Constrictive | Narrow | Wider middle, Tapering top | Low birth rate, Low death rate, Aging population, Slow/Negative growth | Japan |
| Stationary | Moderately wide/Narrow | Gradually tapering | Low birth rate, Low death rate, Stable population, Slow growth | Mexico (transitioning) |
Additional Information: Demographic Transition Model
The shapes of Age-Sex pyramids are closely related to the stages of the Demographic Transition Model. This model describes population change over time as a country develops economically.
- Stage 1 (High Stationary): High birth rate, high death rate. Pyramid: Expansive, wide base, rapidly tapering.
- Stage 2 (Early Expanding): High birth rate, death rate falls rapidly. Pyramid: Very expansive, very wide base, tapering.
- Stage 3 (Late Expanding): Birth rate falls, death rate falls slowly. Pyramid: Expansive, wide base but starting to narrow relatively, less rapid tapering.
- Stage 4 (Low Stationary): Low birth rate, low death rate. Pyramid: Stationary/Constrictive, narrow base, more rectangular middle.
- Stage 5 (Declining): Death rate slightly exceeds birth rate. Pyramid: Constrictive, very narrow base, potentially wider in older ages than young. (Japan is often considered in this stage).
Understanding these stages helps explain why countries like Nigeria and Bangladesh are likely in earlier stages (Expansive pyramid) and countries like Japan are in later stages (Constrictive pyramid).
Important Questions from Population Composition
Arrange the following urban agglomeration in descending order on the basis of population according to 2011 census.
A. Kolkata
B. Delhi
C. Greater Mumbai
D. Bangalore
Choose the correct answer from the options given below:
Which of the following statement(s) about the sex ratio are correct?
(A) Sex ratio shows the socio-economic conditions of women.
(B) Latvia has the highest sex ratio in the world.
(C) Around two-third countries listed by United Nations have sex ratio in favor of females.
(D) Asia has a high sex ratio in favor of females.
Choose the correct answer from the options given below:
In India during 2011, which streams had the highest number of migrants?
Regionally concentrated, self-sustained, and highly specialized High-Tech Industries are known as _____.
Which of the following statements about population distribution in India are correct?
(A) Even spatial distribution of population in India is due to its close relationship with socio-economic, physical, and historical factors
(B) The coastal plains and river plains have high population concentration
(C) The urban regions draw large number of migrants causing high population concentration
(D) India has the highest density of population in the world
Choose the correct answer from the options given below:
