Demographic Shift from Young Emigration

Steps:

• Net emigration means more people aged 20-40 leave than arrive, reducing the working-age population.
• This group represents prime workforce years, so their departure shrinks the youth cohort.
• Remaining population skews older, as fewer young people balance the elderly.
• Result: Higher median age and dependency ratio, defining an ageing population.

Why B is correct:

• Emigration of 20-40 year-olds removes future parents and workers, accelerating population ageing per demographic transition models.

Why the others are wrong:

• A: Reduces overall labor mobility by depleting the active workforce.
• C: Lowers tax base from fewer young contributors, decreasing revenue.
• D: Decreases housing demand from population loss, likely lowering prices.

Final answer: B