Two countries have identical fertility rates. However, Country X is expected to experience much faster population growth than Country Y over the next 25 years. Which factor best explains this difference?

Country X is witnessing population momentum

The correct answer is Option 1: Country X is witnessing population momentum.

Population momentum refers to a situation in which population continues to grow because a large proportion of the population is in or entering the reproductive age group. As a result, even if fertility rates are identical in two countries, the country experiencing population momentum can record faster population growth because a larger number of potential parents contribute to a higher number of births.

Option 2: Country X has a lower literacy rate. — Incorrect. Lower literacy may influence fertility behaviour, but the question already states that fertility rates are identical in both countries.

Option 3: Country X has a higher dependency ratio. — Incorrect. A higher dependency ratio does not necessarily imply faster future population growth.

Option 4: Country X has more metropolitan cities. — Incorrect. The number of metropolitan cities does not directly explain higher population growth when fertility rates are the same.