Understanding Demographics: Key Concepts and Trends
Demographics: The science that studies the population from a quantitative point of view. The task of demographers is to analyze statistics to draw conclusions.
History: Demography was born in the late eighteenth century. The first demographic analysis was made by Thomas Robert Malthus.
Sources for the Study of Population:
- The census counts are regular assessments of people to ascertain their number, age, sex, marital status, occupation, educational level, and purchasing power every ten years.
- The municipal administration maintains a record of all residents in a municipality, updated every five years.
Population Growth: When the birth rate—the number of people born in a specific area—exceeds the death rate, this type of growth is called vegetative or natural growth. The balance of migration is the difference between immigration and emigration. The formula for growth is: Natural Growth = Births – Deaths + Net Migration (Immigrants – Emigrants).
Life Expectancy: This is a demographic indicator that indicates the number of years people can expect to live from the moment of birth.
Demographic Rates: For a more precise understanding of the population:
- Birth Rate: Births in one year / Total population x 1000
- Mortality Rate: Deaths per year / Total population x 1000
- Rate of Natural Increase: Natural increase + Net migration / Population growth rate x 100
- Total Growth: (Population growth + Balance of migration in one year) / Total population x 100
Sex Ratio: More boys are born for the first 30 years, but the ratios equalize. After that, the number of women is higher than that of men.
Age Groups in the Population: The population can be divided into three age groups:
- 0 to 14 years (young population)
- 15 to 65 years (working-age population)
- 65 years and older (aged population)
The percentages indicate whether the population is balanced, young, or aged: 33% young population under 15 years, and 15% aged 65 years and older.
Age Pyramid: This represents the structure of the population by age and sex, showing how many people are young or old.
Young Population: In third-world countries, the age pyramid has a broad base.
Population with a Predominance of Adults: This is represented by a bell-shaped pyramid, typical of countries with large numbers of working-age immigrants.
Aging Population Base: This is characteristic of developed countries with low immigration and low birth rates.
Workforce and Inactive Population:
- Active Population: People who are of working age. The minimum age to work may vary by country, usually starting at age 16.
- Employed Population: Those who are working and earning income.
- Unemployed Population: Individuals who are without work and actively seeking employment.
- Inactive Population: All legal persons of working age who are not employed or seeking work, including those unavailable for work (such as minors).
Types of Economic Activity:
- Primary Sector: Includes all activities related to the exploitation of natural resources (e.g., agriculture, livestock).
- Secondary Sector: Engages in processing raw materials into finished or semi-finished products and energy production (all industrial activities).
- Tertiary Sector: Does not produce material goods; includes activities in the distribution of goods, services, and management (e.g., health, education).
- Quaternary Sector: Involves general service functions or all economic activities related to research and advertising.
The First Demographic Expansion: During the hunter-gatherer stage of prehistoric times, the human population was very low (around 10 million people). Major social, economic, and cultural changes occurred during the Neolithic period, leading to the first demographic expansion.
Home of Progress: The population grew very slowly, with a large number of children due to high mortality rates caused by malnutrition and infectious diseases. Between 1650 and 1850, technical progress, scientific advancements, and increased diversification of crops improved hygienic conditions and food availability, leading to a modern population of approximately 1 billion inhabitants.
Population Explosion: In the second half of the nineteenth century and the first half of the twentieth century, improvements in food production, hygiene, sanitation, and medicine led to decreased mortality rates and high birth rates, resulting in a population of around 7 billion today.
The Current Population: Demographers have shown that gradual and sustained growth can lead to a planetary crisis. It is evident that natural resources are not infinite, nor are the spaces available for habitation.