What should be Total Fertility Rate (TFR) of a population in order to reach at the replacement level of fertility?
- (a)1.0
- (b)1.6
- (c)2.1
- (d)2.3
Correct — C, 2.1. The Total Fertility Rate (TFR) is the average number of children a woman would bear over her reproductive years (15–49) at current age-specific fertility rates. 'Replacement level' is the TFR at which each generation exactly replaces itself. Logically it needs to be a little above 2.0: a woman must be replaced by one daughter and her partner by one son (≈2 children), plus a small margin for girls who die before reaching child-bearing age and for the fact that slightly more boys than girls are born. That margin makes the standard replacement-level TFR ≈ 2.1 in countries with low mortality — which is why (c) is the accepted answer.
- (a)1.0 — Wrong — a TFR of 1.0 is far below replacement; a population with about one child per woman would shrink rapidly each generation.
- (b)1.6 — Wrong — 1.6 is a 'below-replacement' rate typical of ageing low-fertility societies; it does not replace the parent generation.
- (d)2.3 — Wrong — 2.3 is above replacement (mild growth). Replacement level is pegged at about 2.1, not 2.3, in low-mortality populations; 2.3 is a distractor set just above the correct value.
Total Fertility Rate (TFR) is the average number of live births a woman would have by the end of her child-bearing years if she experienced the prevailing age-specific fertility rates. Replacement-level fertility is the TFR that keeps a population's size constant across generations (ignoring migration). Because a couple must produce roughly two surviving children and a small allowance is needed for pre-reproductive mortality and the slight excess of male births, the replacement TFR is about 2.1, not exactly 2.0.
The trap is to answer 2.0 by simple 'two-to-replace-two' logic. Prelims tests whether you remember the ~0.1 adjustment for mortality and sex ratio at birth. India's own TFR fell to about 2.0 in NFHS-5 (2019–21) — at or just below replacement — which is why this figure is a recurring exam favourite.
- TFR = average number of children per woman over ages 15–49 at current fertility rates
- Replacement-level fertility ≈ 2.1 in low-mortality populations
- The extra ~0.1 above 2.0 covers childhood mortality and the slight male-biased sex ratio at birth
- India's TFR reached about 2.0 in NFHS-5 (2019–21), at/just below replacement
Answer (c) 2.1: exactly 2.0 would replace parents only if every girl survived to reproduce and births were 50:50 — they don't, so a margin is added.
- Answering 2.0 by naive 'two replaces two' reasoning and missing the ~0.1 margin
- Confusing TFR (per woman, lifetime) with the Crude Birth Rate (births per 1000 population per year)
UPPSC/UPSC ask this directly ('replacement-level TFR = ?') or by asking you to define/rank TFR against CBR and NRR.
The total fertility rate in an economy is defined as :
- (a) the number of children born per 1000 people in the population in a year
- (b) the number of children born to a couple in their lifetime in a given population
- (c) the birth rate minus death rate
- (d) the average number of live births a woman would have by the end of her child-bearing age
Answer(d) the average number of live births a woman would have by the end of her child-bearing age
Same concept — the definition of TFR. UPSC 2024 asks what TFR means; this 2020 question applies that definition to identify the replacement-level value (2.1).
- practice — not a real PYQ
Total Fertility Rate (TFR) is best defined as the
- (a)number of live births per 1000 population in a year
- (b)average number of children a woman would bear during her reproductive years
- (c)excess of birth rate over death rate
- (d)number of female children per 1000 male children
Answer(b) average number of children a woman would bear during her reproductive years — at current age-specific rates.
- practice — not a real PYQ
A population with a Total Fertility Rate persistently below 2.1 will, other things being equal,
- (a)eventually decline in size across generations
- (b)grow exponentially
- (c)remain exactly constant forever
- (d)double every generation
Answer(a) eventually decline in size across generations — it is below replacement level.