The demographic dividend, which has begun in India and is expected to last another few decades, is a great window of opportunity. The demographic dividend is basically a swelling in the working age population, which conversely means that the relative ratio of very young and very old will, for a while, be on the decline. From the experience of Ireland and China, we know that this can be a source of energy and an engine of economic growth. The demographic dividend tends to raise a nation’s savings rate since in any nation, it is the working age population that is the main saver. And since the savings rate is an important driver of growth, this should help elevate our growth rate. However, the benefits of demographic dividend depend on the quality of the working age population. And this implies bringing back the importance of education, acquisition of skills and human capital.

Which of the following would invariably happen in a country, when the demographic dividend has begun to operate?
1. The number of illiterate people will decrease.
2. The ratio of very old and very young will decrease for a while.
3. Population growth rate will quickly stabilize.
Select the correct answer using the code given below.

The correct option is 2 only.

Let us analyze the statements based on the provided passage to understand why only the second statement must invariably happen:

1. Analysis of Statement 1: "The number of illiterate people will decrease."
The passage mentions that the benefits of the demographic dividend depend on the quality of the working-age population, which "implies bringing back the importance of education, acquisition of skills and human capital." However, the onset or operation of the demographic dividend itself is defined purely by population age structures (a swelling in the working-age population). It does not automatically guarantee or cause a decrease in the number of illiterate people unless active education policies are successful. Thus, this does not invariably happen simply because the demographic dividend has begun to operate.

2. Analysis of Statement 2: "The ratio of very old and very young will decrease for a while."
The passage explicitly defines the demographic dividend as "a swelling in the working age population, which conversely means that the relative ratio of very young and very old will, for a while, be on the decline." Since this decline in the ratio of the non-working-age population (very young and very old) to the working-age population is the fundamental definition of the demographic dividend, this event will invariably happen when the dividend operates.

3. Analysis of Statement 3: "Population growth rate will quickly stabilize."
The passage discusses the economic impacts of a swelling working-age population and the transition in age structure, but it does not state or imply that the overall population growth rate will "quickly stabilize" as an immediate or invariable consequence of the demographic dividend beginning to operate. Population stabilization depends on long-term fertility rates and demographic transitions that are not guaranteed to happen quickly just because the working-age cohort is currently large.

Therefore, only statement 2 is correct and will invariably happen.