Correct Option: B. High dependency ratio Explanation of the Correct Answer A high dependency ratio refers to a situation where a large proportion of the population is made up of dependents—typically children (aged 0-14) and the elderly (aged 65 and over)—compared to the working-age population (aged 15-64). This demographic structure can have significant implications for a country’s economy and social services.

1. Understanding Dependency Ratio:
2. The dependency ratio is calculated using the formula: [ \text{Dependency Ratio} = \left( \frac{\text{Number of Dependents}}{\text{Working-Age Population}} \right) \times 100 ]
3. A high dependency ratio indicates that there are many more dependents relative to those who are working and contributing to the economy. This can strain resources, as fewer workers are available to support the needs of the dependents.
4. Economic Implications:
5. With a high dependency ratio, the working population may face increased pressure to provide for the dependents. This can lead to higher taxes and reduced disposable income for families, as more government resources are allocated to support social services for children and the elderly.
6. Countries with high dependency ratios may struggle to invest in infrastructure, education, and healthcare, as a significant portion of their budget is directed towards supporting dependents.
7. Social Services:
8. A high dependency ratio often results in increased demand for social services such as education, healthcare, and pensions. Governments may find it challenging to meet these demands, leading to potential shortfalls in service provision.

Why the Other Options Are Incorrect

• A. A large productive labour force:
• This option is incorrect because a high dependency ratio typically indicates that there are fewer people in the productive age group compared to dependents. A large productive labor force would suggest a lower dependency ratio, where more individuals are contributing economically.
• C. Relatively low investment in social services:
• While a high dependency ratio can strain resources, it often leads to increased investment in social services to support the dependents. Therefore, this option is misleading. Countries with high dependency ratios usually need to invest more in social services to cater to the needs of children and the elderly.
• D. High life expectancy:
• High life expectancy is not directly related to a high dependency ratio. A population can have a high dependency ratio due to a large number of children, regardless of life expectancy. Additionally, high life expectancy can sometimes lead to a higher dependency ratio if there are many elderly individuals, but it does not inherently imply a high dependency ratio.

Summary of Key Points

• A high dependency ratio indicates a large proportion of dependents compared to the working-age population.
• It can lead to economic strain, as fewer workers support more dependents, impacting taxes and disposable income.
• Increased demand for social services often accompanies a high dependency ratio, requiring more government investment.
• Understanding the implications of population structure is crucial for effective policy-making and resource allocation.

This thorough understanding of the dependency ratio and its implications will help you grasp the broader concepts of population dynamics in geography.