1.1 Population dynamics: Describe and suggest reasons for population increase and decrease.

📈 Population increase happens when the number of people in a place grows. 📉 Population decrease occurs when the number of people shrinks. Think of a city as a garden: if you plant more seeds (births) than you remove (deaths), the garden gets bigger. If you pull out more seeds than you plant, the garden gets smaller.

• Birth rate (number of births per 1,000 people)
• Death rate (number of deaths per 1,000 people)
• Immigration (people moving in)
• Emigration (people moving out)
• Government policies (e.g., one-child policy, family planning)
• Economic opportunities (jobs, wages)
• Health and medicine (vaccines, hospitals)
• Education levels (especially for women)

The change in population can be expressed as:
$P_{t+1} = P_t + B - D + I - E$
Where:
$P_t$ = population at time t
$B$ = births
$D$ = deaths
$I$ = immigration
$E$ = emigration

1. High birth rates in rural areas where families need more hands to work the land.
2. Low death rates due to improved healthcare and sanitation.
3. Immigration from neighboring countries seeking better jobs.

1. High death rates caused by disease outbreaks.
2. Low birth rates because families choose to have fewer children.
3. Emigration of young people to cities or abroad for better opportunities.

India’s higher birth rate and positive migration keep its population growing, while Japan’s low birth rate and higher death rate lead to a shrinking population.

👉 Remember: When answering “Why does population increase/decrease?”, list at least four causes and give a short example for each. 📌 Use the population growth formula to show how the factors combine. 📌 Include a real-world example (like India or Japan) to demonstrate your understanding. 📌 Keep your answer clear and concise – aim for 3–4 sentences per factor.

• What is the difference between birth rate and death rate?
• How does immigration affect a country’s population?
• Give one reason why a developed country might experience population decline.