How do the gross reproductive rate and the net reproductive rate differ?

Short Answer

Expert verified
Gross Reproductive Rate (GRR) calculates the average number of female offspring born to a female during her reproductive lifetime, giving an overview of the potential for population growth. In contrast, Net Reproductive Rate (NRR) calculates the average number of female offspring born to a female during her reproductive lifetime, taking into account both fertility rates and the likelihood of survival to reproductive age. The main differences between GRR and NRR are: 1. GRR only considers the number of female offspring produced per woman in each age group, whereas NRR also incorporates age-specific survivorship rates of the female population. 2. GRR provides a simple measure of potential population growth, while NRR offers a more comprehensive and realistic representation of population growth potential, accounting for mortality rates before reaching reproductive age. 3. A GRR value of 1 indicates no potential for population growth or decline, while a NRR value of 1 indicates a stable population where females are exactly replacing themselves.

Step by step solution

01

Define Gross Reproductive Rate (GRR)

Gross Reproductive Rate (GRR) is a demographic measure that calculates the average number of female offspring born to a female during her reproductive lifetime. This value gives an overview of the potential for population growth.
02

Define Net Reproductive Rate (NRR)

Net Reproductive Rate (NRR) is another demographic measure that calculates the average number of female offspring born to a female during her reproductive lifetime, but it also takes into account the likelihood of survival to reproductive age and fertility rates. Unlike GRR, NRR provides a more realistic representation of population growth potential, as it accounts for the mortality rate before reaching reproductive age.
03

Discuss Calculation of GRR and NRR

Both GRR and NRR involve summing up the products of age-specific fertility rates and female offspring produced for all relevant age groups. However, there is a difference in their calculation: 1. GRR only considers the number of female offspring produced per woman in each age group. \(GRR = \sum l_b m_x\) 2. NRR, on the other hand, also incorporates the age-specific survivorship rates (\(l_x\)) of the female population. \(NRR = \sum l_x m_x\) Here, \(l_x\) is the probability of survival to age \(x\), \(l_b\) is the probability of survival to birth, and \(m_x\) is the age-specific fertility rate for females at age \(x\).
04

Compare Interpretation of GRR and NRR

- GRR gives the average number of female offspring produced by a female throughout her reproductive life, without considering the survival of those offspring. A GRR value of 1 indicates no potential for population growth or decline. - The NRR considers both fertility and survival rates, providing a more comprehensive view of the actual population growth potential. A NRR value of 1 indicates a stable population, where females are exactly replacing themselves. If the NRR is greater than 1, the population is growing, and if the NRR is less than 1, the population is declining. In summary, GRR is a more simplistic measure looking only at the number of female offspring, whereas NRR considers both fertility and survival rates, providing a more accurate outlook on population growth potential.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Study anywhere. Anytime. Across all devices.

Sign-up for free