Falling Death Rates, Not Rising Birth Rates, Set Off the Population Boom

Crowded trains, long queues at hospitals and competition for seats in colleges all come back to one thing: the number of people sharing the same land, water, jobs and services.

Population rises when births outnumber deaths. This chapter covers how population is measured, why it grew so fast, the problems that rapid growth brings, and the methods used to control it.

Demography is the statistical study of human population, population density is the number of people per square kilometre, birth and death rates are the numbers of births and deaths per 1000 people in a year, and the growth rate is the difference between them.

- Demography — the study of population size, density, distribution, births, deaths and age structure
- Population density — number of people living in one square kilometre
- Birth rate — number of live births per 1000 people per year
- Death rate — number of deaths per 1000 people per year
- Growth rate — birth rate minus death rate, often given as a percentage

Worked example. A town of $50000$ people covering $25{\text{ km}}^2$ records $1200$ births and $400$ deaths in a year.

$$\text{density}=\frac{50000}{25}=2000{\text{ per km}}^2$$
$$\text{birth rate}=\frac{1200}{50000}\times 1000=24\text{death rate}=\frac{400}{50000}\times 1000=8$$
$$\text{growth rate}=24-8=16\text{ per }1000=1.6\%$$

An everyday example. During a census, workers visit every household to record the details that demographers later use to calculate these rates.

The substance. A high density does not by itself mean a place is overpopulated; that depends on the resources available to the people living there.

The population rose sharply because death rates fell steeply with better medicine, food and sanitation, while birth rates stayed high for social and economic reasons.

Reasons for the fall in death rate:

- Vaccines and antibiotics control diseases that once killed large numbers of people
- Epidemics are controlled better, and smallpox has been eradicated
- Safer drinking water and sanitation reduce infections
- More food from improved farming reduces famine
- Fewer infants die, and people live longer

Reasons birth rate stayed high:

- Early marriage lengthens the years in which children are born
- Children seen as extra earners or as support in old age
- Preference for sons, leading to more births
- Lack of education and awareness of family planning

An everyday example. Vaccination sessions at anganwadis and health centres protect children from diseases that were once common causes of early death.

The substance. Population keeps rising whenever the birth rate is above the death rate, even if the birth rate itself is slowly falling.

A population explosion leads to unemployment, over-use of natural resources, low income per person, rising prices, more pollution and a widening gap between rich and poor.

- Unemployment — jobs do not increase as fast as the number of people seeking them
- Over-exploitation of natural resources — forests are cut, groundwater is over-drawn and fuels are used up faster
- Low per capita income — the same national income is shared among more people
- Price rise — demand for food, housing and goods grows faster than supply
- Pollution — more vehicles, more waste and more sewage
- Unequal distribution of wealth — resources concentrate with a few while many remain poor
- Pressure on services — overcrowded schools, hospitals, housing and transport

Worked example — per capita income. Suppose a village earns ₹60 lakh a year in total.

$$\text{with }1500\text{ people: }\frac{6000000}{1500}=\text{₹}4000\text{with }2000\text{ people: }\frac{6000000}{2000}=\text{₹}3000$$

The same income gives each person a quarter less.

An everyday example. In many towns, borewells now have to be dug much deeper than before, because more people are drawing on the same groundwater.

The link. Each problem follows from the causes above: more people surviving and being born, but land, water and jobs not growing at the same pace.

Population education makes people aware of how population growth affects their lives and encourages small families, while contraceptive methods such as barriers, pills, intrauterine devices and surgery prevent unplanned pregnancies.

Population education

- Awareness of the effects of rapid population growth
- Encourages the small family norm, marriage at the legal age and education of girls
- Explains family planning methods and where to get them

Methods of population control

- Condoms — a barrier that stops sperm reaching the ovum; also protects against sexually transmitted infections
- Contraceptive pills — contain hormones that prevent ovulation
- Intrauterine devices (IUDs), such as the Copper-T — placed in the uterus by a doctor; prevent fertilisation or implantation
- Vasectomy — a small operation in which the vas deferens is cut and tied, so sperm cannot enter the semen
- Tubectomy — the fallopian tubes are cut and tied, so the ovum cannot meet sperm

Temporary methods can be stopped; vasectomy and tubectomy are permanent.

An everyday example. Government health centres offer family planning advice and services free of charge.

The substance. Only condoms also protect against sexually transmitted infections; the other methods prevent pregnancy alone.