World Population and Migration: Trends and Factors
World Population: Trends and Factors
World population refers to the total number of inhabitants. Population density is the relationship between people and surface area. Areas can be classified as:
- Sparsely populated: About 10 inhabitants/km2
- Moderately populated: 50-80 inhabitants/km2
Population evolves through several factors:
- Birth rate: The number of births in a population.
- Fecundity: The average number of children a woman is expected to have.
- Mortality: The number of deaths in a population.
- Migrations: Movements of people.
Historical Population Growth
The global population grew slowly until the 14th century due to high birth rates, high mortality, and a lack of medical advances.
Demographic Explosion
From the 14th century onward, the population grew rapidly due to decreasing mortality rates, improvements in agricultural techniques (leading to more food), and advances in medicine and hygiene.
Current Situation and Projections
The largest growth is currently experienced in developing countries, which have a younger population. In the 21st century, the population is expected to age, with fewer children being born.
High Growth in Underdeveloped Countries
High birth rates in underdeveloped countries are influenced by:
- The majority of the population relies on agriculture, and children working in agriculture are important.
- High infant mortality rates (92 children under five years old die per 1000 births annually).
- Cultural values related to the number of children women have.
- Religious beliefs that reject the use of artificial birth control methods.
- Lack of government family planning campaigns.
Lower Life Expectancy and Youth in Developing Countries
Life expectancy is lower in developing countries compared to developed countries. The diffusion of drugs and vaccines has reduced mortality, but many people still lack access to healthcare and potable water.
Problems and Policies Related to Rapid Population Growth
Rapid population growth increases pressure on natural resources, requires more services and housing, and can lead to insufficient jobs.
High Growth and Low Birth Rates
Low birth rates are influenced by:
- Progressive incorporation of women into the workforce.
- Diffusion of contraceptives.
- Delay in the age of forming a family.
- High expenses associated with raising children.
- Shifts in social values and a lower influence of religion.
High Life Expectancy and Aging in Developed Countries
The average life expectancy exceeds 79 years in developed countries, leading to an aging population. This presents several problems and policy challenges:
- Increased state expenditures on healthcare and care centers for seniors.
- Increased expenditure on pensions.
- An older, potentially less adaptable workforce, which can slow economic growth.
- A more conservative population, which may present an obstacle to new development initiatives.
Migration
Definition and Causes
Migration refers to all population movements. Emigration is the movement of people *from* a place, while immigration is the arrival of people *to* a place. The main causes of migration are:
- Economic reasons (the majority of migrations).
- Political reasons.
- Natural disasters (e.g., earthquakes).
Types of Migration
Migrations can be classified based on:
- Character: Forced or voluntary.
- Duration: Temporary or definitive.
- Location: Internal (within a country) or external (international).
Current Migration Patterns
Internal or National Migration
- Developing countries: Displacement of rural people to urban areas.
- Developed countries: Migration for education or employment.
External or International Migration
- From less developed to developed countries: Usually workers in fields like agriculture and cleaning.
- Among developed countries: People seeking specialized jobs not available in their home country.
- Among less developed countries: Various reasons, often related to economic opportunities or conflict.