Global Population Dynamics: Growth, Demographics, and Trends

• Phase 1: Former Demographic Regime: Birth rates and mortality rates are very high, so natural population growth is very slow or non-existent.

• Phase 2: Start of Demographic Transition: Mortality rates fall suddenly due to improvements in agricultural techniques (increasing returns), technology, medicine, and literacy. These changes extend life expectancy and reduce mortality.

• Phase 3: End of Transition: Birth rates decline due to access to contraception, women’s education and labor market participation, access to welfare, urbanization, the shift from subsistence to commercial agriculture, and other societal changes.

• Phase 4: Modern Demographic Regime: Mortality rates bottom out, and birth rates equalize, causing natural population growth to stagnate again.

Applying this model and observing the deceleration of population growth, humanity is entering phase 4, while some industrialized countries have already passed it, and developing countries are in stage 2.

There is also speculation about a Stage 5 in more advanced countries, showing negative population growth because the birth rate falls below the death rate (aging population) (on population demographics).

Indicators and Definitions

• Human Population: In demographics, this is a group of people residing in a well-defined geographic area, characterized by:

• Dimension: Also called size or population size, it is the number of persons in that population.

• Space: The geography where the population is based.

• Structure: Biological and social characteristics define the population, such as age, sex, marital status, place of birth, nationality, language spoken, educational level, economic status, and fertility.

• Evolution: The set of dynamic variables that change over time, such as fertility, mortality, migration, and their derived rates, proportions, and ratios. The Earth’s surface has a production capacity that limits human population increase.

Terms Used in Demography

Demography is the discipline studying population dynamics, using its own vocabulary. Some basic demographic concepts linked to vegetative dynamics are:

• Stock or Actual Population Demographics: A given population at a specific time, usually a census year. It integrates the concepts of:
  • Population de jure or de facto: Composed of present individuals and bystanders. The denominator is usually the main algorithms to calculate rates.
  • Population de jure: Made up of registered voters, both present and absent.
• Population Density: This calculation estimates how many people are in a region. It is the number of inhabitants divided by the region’s area in square miles.
• Birth Rate: The number of children born per thousand people each year in a place.
• Death Rate: The number of people who die per thousand inhabitants in a place each year.
• Vegetative Growth Rate: The difference between the number of births and deaths in a year in one place.
• Crude Birth Rate
• Crude Mortality Rate
• Population Growth Rate
• General Fertility Rate
• Fertility Rate
• Total Fertility Rate
• Migration: The population does not stay in the same region; people constantly change residence between cities or countries. The transfer can be for a long-term change of address or a short vacation. These movements are called migration, influencing population distribution and density. A person leaving a place is said to emigrate; arriving, they are called an immigrant. As a country moves from an agricultural to an industrial economy, there is large-scale migration from rural areas to cities. In this process, the growth rate of urban areas doubles the overall population growth rate.