Simple Explanation
Low fertility long-term younger cohorts reduce कर सकती है, but immigration often working-age adults को city में लाती है। इससे labour force size and age structure otherwise expected ageing से different रह सकते हैं। इसलिए पहला विकल्प सही है। Expert analysis में natural increase and migration composition दोनों को demographic distribution समझने के लिए jointly consider करना चाहिए। / Low fertility can reduce younger cohorts over time, but immigration often brings working-age adults into a city. This can keep the labor force and age structure younger than would otherwise be expected. Therefore, the first option is correct. Expert analysis should jointly consider natural increase and the composition of migration when explaining demographic distribution.
