Meaning and Scope of Population Studies

1. Meaning and Scope of Population Studies

Demography is the systematic study of human population — its size, growth, composition

(age, sex, literacy, occupation), distribution across space, and the processes (birth, death,

migration) that change it over time. The word comes from the Greek demos (people) and

graphein (to describe/write) — literally, "writing about people."

Demography studies population from two complementary angles:

• Quantitative aspects — HOW MANY people there are, how fast that number is changing, and how they are spread across regions (size, growth rate, density, distribution).
• Qualitative aspects — WHAT KIND of population it is: its age structure, sex ratio, literacy rate, occupational structure, and standard of living.

Why economists study population. Population is not just a passive fact sitting alongside

the economy — it is one of the economy's own core inputs and outputs at once:

• It supplies the labour force that produces the country's output.
• It is the market that consumes what is produced.
• Its size and growth rate determine how much of any increase in national output must simply be "absorbed" by more mouths to feed, before per capita income (income per person, the real measure of a population's living standard) can rise at all.
• Government planning — how many schools, hospitals, houses, and jobs a country needs to build — depends directly on accurate population data and projections.

This is why India conducts a nationwide Census every ten years (the last completed Census

was in 2011) — an official, direct headcount that is the single most authoritative primary

source for every population fact used in economic planning, including everything covered later

in this chapter.