This tutorial will cover the topic of population growth, through the definition and discussion of:
There are many factors that affect population growth or population stability in the long term. Many social scientists also consider themselves to be demographers. Demography is the empirical study of groups of people, of populations. Demographers study the characteristics of a population as a whole. It's a more quantitative way to look at the social world--demographers are interested in population and factors that affect population.
Demographers have a formula for population in society:
Population (P) equals births (B) minus deaths (D), plus a variable for migration, which is immigration (I) minus emigration (E).
Immigration represents people coming in to an area or country, and emigration is the outflow of people--people going out of a country. Demographers are interested in social variables that might affect birth rates, such as education, job opportunities for women, and the availability of contraceptives. Similarly, the level of medical advancement might affect death rates. As you can see, there are many social factors that sociologists are interested in that affect the variables in this equation.
Breaking the formula down into its component parts, there are several factors that contribute to increase populations.
Fertility is the ability of an individual or a group--a population--to conceive children. It follows that fertility can increase population.
2. Birth Rate
Birth rate is the rate of births over a specific time--typically, births in a single year per 1,000 people. For instance, if 100 babies are born in American society in 2012 per every 1,000 people, this equates to a birth rate of 100 births per 1,000, or a birth rate of 10%.
Immigration is a form of migration, which is the movement of people either into or out of a population. Immigration is the movement of people into a population, which can affect population as well.
What are the factors that might decrease a population?
Mortality is a measurement of how frequently death occurs within a population, as is the death rate, which is the measure of deaths over a specified period of time. Similar to the calculation of birth rate, it's typically the number of deaths per 1,000 people. Infant mortality rate is a specific kind of mortality that measures the rate of death for children that are under one-year-old.
The United States does not have a very high infant mortality rate. Infant mortality rate, like the other variables under discussion, is related to societies. It's related to social progress and evolution.
Emigration is the movement of people out of a population.
Circling back to the formula, population equals the number of births minus the number of deaths, which provides one variable, added to the migration variable (immigration minus emigration).
Finally, balancing everything, there is the measure of life expectancy. Life expectancy is the average year to which somebody will live in a given society. It varies by society and also between men and women.
In the United States, women have a longer life expectancy than men by a few years. However, this statistic might be different in other societies. Life expectancy is a social variable--it’s related to society and the level of social advancement.
Today you explored a descriptive overview of demography and the population formula, and the factors affecting population growth or decline in society. You also learned about life expectancy, the average year to which somebody will live in society.
Source: This work is adapted from Sophia author Zach Lamb.
A rate of births over a specific time (normally expressed as x per 1,000 people).
A rate of deaths over a specific time (normally expressed as x per 1,000 people).
The empirical study involving the structure of human populations.
The ability to conceive children, which is measured statistically and referred to as birth rates.
A rate of deaths of children under 1 year old over a specific time (normally expressed as x per 1,000 people).
The average years of life for a person within a group or population.
Movement of people into or out of an area.
Measuring how frequently death occurs in a given population.