Demography is the science that studies human populations, their characteristics, and their evolution over time . Thus, demographers’ task is to statistically describe the size, spatial distribution, and composition of the populations under study.
Demographic research involves quantitative analyses that measure elements of interest in a population, such as:
- the fertility and mortality rates,
- the age structure (age),
- the population density of a territory,
- migration,
- life expectancy,
- population growth or decline, etc.
Both statistical methods and tools borrowed from fields such as economics, history, and sociology help demography study highly relevant social phenomena. These include the assessment of a society’s demographic trends , their historical understanding, and their future projections.
Demographic information thus becomes essential in public policy planning . While it helps public and private entities understand the sociocultural and economic inclinations of a population, it also helps governments prepare for the administration of health services, urban planning, education, and other areas.
Characteristics of demographics
Focus on quantitative studies . It uses statistical methods to analyze numerical data about populations, that is, demographic data that allow for the identification of patterns and trends (growth, aging, migration, etc.).
Interdisciplinary science . It draws on other sciences to explain how demographic processes are related to socioeconomic, geographic, and historical aspects.
Theorizing based on statistical results . It seeks to explain when and why events that affect populations occur. The data show a reality, for example, the increase in life expectancy in developed countries. Answers are then proposed as to why this is so.
Formulating projections and predictions . Demographic models estimate how populations will evolve based on different scenarios.
Application in public policy design . It provides information to government agencies so they can adapt their social programs based on the needs or characteristics of the population.
Types of demographics
Demographics can be divided according to the time frame of reference for studying a population, or according to the demographic components being analyzed . Thus, we have:
Static demographics
Static demography studies the structure of a population at a given time . It describes the population size (dimension) distributed within a specific territory (continental, regional, local, etc.).
The demographic structures or aspects it addresses include sex, age, marital status, educational level, socioeconomic status, language spoken, or nationality of individuals within the population. The purpose of static demography is to describe the composition of the population during a given period.
Example : National censuses aim to collect data on a country’s entire population. This provides an understanding of the various characteristics of a population at a given time.
Population pyramids contain a statistical portrait of the nation, or of the different segments of its population.
Dynamic demographics
Dynamic demography studies the evolution of populations over time. In general, it seeks not only to describe but also to explain the changes that populations experience by analyzing fertility, mortality, and migration rates, among other phenomena, over the course of history.
By taking into account the variables that affect a population, demographers can observe the changes that have occurred and, likewise, make projections or estimates of the future evolution of those populations.
Example : comparative studies of fertility rates in European countries in the 19th, 20th, and 21st centuries. A quantitative comparison of the data reveals a gradual decline in the rate in the second half of the 20th century, a trend that continues to the present, and which marks similar trends on the horizon.
You may be interested in Birth rate .
Now we’ll look at the types of demographics based on the object of analysis. These include:
Demogeography, or demographic geography
Demographic geography focuses on analyzing the spatial distribution of human populations . It examines population density across territories. It also focuses on data inherent to rural and urban populations.
Example : studies on the migration of communities from the countryside to the city.
Historical demography
Historical demography is related to and forms part of dynamic demography. A distinguishing feature of the nomenclature is that historical demography examines population changes exclusively in past periods. It does not usually attempt to make future projections.
Historical demography is used to understand the transformations of a population in its temporal context, using historical documents as a source.
Example : studies of the effects caused by wars or pandemics, or the vigorous growth caused by processes such as the Industrial Revolution, and advances in medicine.
Social demography
It studies the impact of social factors on population composition. In this regard, it examines aspects such as family structure, the religious affiliation of community members, educational background, the types of housing people live in, etc.
Example : research on the impact of education on women and its impact on the fertility rate in developed urban societies.
See also: Population and Human Geography
Father of demography
Since ancient times, there have been thinkers who have studied populations. Therefore, it is not easy to attribute the title of father of demography to a single individual. Even so, experts point to the 14th-century Arab historian Ibn Khaldun as one of the forerunners of this discipline.
In Ibn Khaldun’s texts, one can trace ideas about the relationship between populations and the environment in which they developed. He also observed the composition of societies and their cycles of growth and decline.
In the English-speaking world, John Graunt (1620–1674) is considered the father of demography . In his work, Natural and Political Observations Made upon the Bills of Mortality (1662), Graunt carried out statistical analyses of birth and death rates in the city of London.
Other social scientists point to the influence of Thomas Malthus (1766–1834) on the advancement of modern demography. In An Essay on the Principle of Population (1798), Malthus developed his controversial and influential theory about the difficulties generated by population growth and the lack of sufficient resources to sustain it.
