1. Mortality 

Mortality refers to the occurrence of death in a population. Mortality rates are used as a measure of the health status of a population and are an important component of demographic analysis. Mortality rates can be measured in different ways, but the most common measures include: 

• Crude Death Rate (CDR): The number of deaths per 1,000 population in a given year. 
• Age-Specific Death Rate: The number of deaths per 1,000 population in a specific age group in a given year. 
• Infant Mortality Rate (IMR): The number of deaths of infants under one year of age per 1,000 live births in a given year. 
• Maternal Mortality Rate (MMR): The number of maternal deaths due to pregnancy or childbirth-related complications per 100,000 live births in a given year. 

2. Fertility  

Fertility and population growth are closely linked, as fertility levels determine the number of births and hence the rate of population growth. Fertility refers to the number of children born to women of childbearing age (usually defined as ages 15-49) in a given population. 

The components of fertility are as follows: 

• Crude Birth Rate (CBR): The crude birth rate is the number of live births per 1,000 population in a given year. It is the most basic measure of fertility and provides a rough estimate of the level of fertility in a population. 
• General Fertility Rate (GFR): The general fertility rate is the number of live births per 1,000 women of childbearing age (usually defined as ages 15-49) in a given year. It provides a more refined measure of fertility and takes into account the age distribution of women in the population.
• Age-Specific Fertility Rate (ASFR): The age-specific fertility rate is the number of live births to women in a specific age group (usually in five-year intervals) per 1,000 women in that age group in a given year. ASFRs provide a more detailed picture of the distribution of fertility across different age groups of women. 
• Total Fertility Rate (TFR): The total fertility rate is the average number of children that a woman would have over her lifetime if she were to experience the age-specific fertility rates of a given year. It is a more comprehensive measure of fertility that takes into account the entire reproductive period of women and provides an estimate of the number of children that a cohort of women would have over their lifetimes. 
• Completed Fertility: Completed fertility is the total number of children ever born to women by the end of their reproductive years. It provides a retrospective measure of fertility and takes into account both the age at which women start having children and the age at which they stop. 

Determinants of High Fertility Rates in India 

There are several determinants of high fertility rates in India, including: 

1. Early age of marriage: The age of marriage in India is still relatively low, particularly in rural areas. Early marriage often leads to early childbearing, which can contribute to higher fertility rates. 
2. Lack of access to family planning services: Despite the government's efforts to increase access to family planning services, many people in India still lack access to modern contraceptive methods, leading to unintended pregnancies and higher fertility rates. 
3. Low levels of education: Education, particularly for women, has been shown to have a strong negative correlation with fertility rates. In India, particularly in rural areas, access to education is limited, particularly for girls. 
4. Patriarchal social norms: Gender roles and social norms in India are often patriarchal, with men typically holding more power in decision-making around reproduction. This can limit women's ability to make choices about their own reproductive health, including the number and spacing of their children. 
5. Traditional values and beliefs: In some parts of India, large families are still considered a sign of wealth and social status, and having many children is seen as a cultural and religious norm. 
6. Lack of economic opportunities: In many parts of India, particularly in rural areas, lack of economic opportunities can limit families' ability to invest in their own future, leading to a higher reliance on having more children for economic security. 
7. Low awareness of reproductive health: There is still a lack of awareness about reproductive health in many parts of India, particularly among marginalized communities. This can lead to misconceptions about contraception and reproduction, contributing to higher fertility rates. 

Declining TFR 

There are several reasons behind declining trends of TFR, including: 

1. Improved access to family planning services: In India, the use of modern contraceptive methods has increased from 13.9% in 1970 to 48.5% in 2015-16. The government has also increased the number of family planning clinics and services, making them more accessible to people across the country. 
2. Education: Education, especially for girls, has been shown to have a strong negative correlation with fertility rates. According to the National Family Health Survey (NFHS) 2015-16, the fertility rate of women who have completed secondary education or higher is 1.7 children per woman, compared to 2.6 children for women with no education. 
3. Economic development: India's per capita income has more than tripled from $402 in 2000 to $1,362 in 2020, leading to improvements in living standards and health outcomes. As families become more focused on quality of life and invest in the future of their children, they are more likely to have fewer children. 
4. Social changes: Social changes, such as urbanization, delayed marriage, and changing attitudes towards family size, have also contributed to declining fertility rates in India. The proportion of India's population living in urban areas has increased from 17.3% in 1950 to 34% in 2020, leading to changes in lifestyle and family planning behavior. 
5. Population control programs: India's population control programs have been in place since the 1960s, and have included incentives for family planning, mass media campaigns, and targeted education programs. According to the NFHS 2015-16, the percentage of women who have heard of family planning methods has increased from 48% in 1992-93 to 97% in 2015-16.