Topic 2.3: Population Composition and Pyramids

Core Elements: Age and sex are the foundational components used to depict, analyze, and understand the past, present, and future demographic trends of a region.
Gender Imbalances: Disparities between male and female populations are driven by gender-selective migration, conflict casualties, and cultural practices or preferences.

Alternate Designation: Also designated as an age-sex pyramid or age-sex structure diagram.
Key Diagram Components:
- Horizontal Axis: Separated into Male cohorts on one side and Female cohorts on the other.
- Vertical Axis: Measures population distribution divided by Age Group cohorts, extending up through the 100- age bracket.
Inferred Data: Illustrates dependency burdens, cohort survival, life expectancy, sex ratios, and historical demographic disruptions.

Triangle Shape (Wide Base, Skinny Top): Signifies high birth rates, high infant dependency, and rapid overall population growth.
Even Structure on Both Sides: Reflects stationary or zero growth, balanced birth and death rates, and an even distribution across age cohorts.

Impact of War: Causes visible inward notches or indentations, primarily in military- and reproductive-age cohorts (especially males), combined with a temporary collapse in fertility.
Birth Deficit: A significant slowdown or drop in the birth rate directly caused by a period of conflict, economic stress, or crisis.
Baby Booms, Busts, and Echoes (p.67):
- Baby Boom: A rapid, marked increase in birth rates over an extended post-crisis period.
- Baby Bust: A sharp decline in births following the conclusion of a boom.
- Echo: A secondary surge in births emerging when the baby boom cohort reaches peak childbearing years.