Demography is the scientific study of characteristics and dynamics pertaining to the human population, including things like size, growth rate, density and distribution of a specified group. It requires the study of information that may be gathered from a population census, vital statistic records and other sources. People who study and record this data are referred to as demographers, and they must know both how to scientifically obtain facts and how to interpret them relatively. Used for thousands of years, it has a wide range of practical applications and has evolved over time.
Main Goal and Importance
The primary reason people use demography is to create statistics--in fact, the term roughly translates to "people measurement." These allow a person to get a picture of how common specific traits within a group are, or to determine elements such as risk. The numbers are not arbitrary and are based on facts, so although individuals have to be careful not to let bias slide into their collection methods, people see the resulting percentages or ratios as a more scientific way of supporting a point or coming to a conclusion about a population. Comparing statistics over time also allows researchers to show changes that are happening in the target group, which is very useful for planning purposes.
Key Statistical Concepts
The information gathered and studied for a demographic overview of a population depends on the person or group that will be using it, but statistical concepts essential to this field include birth, death, infant mortality, and fertility rates, as well as life expectancy. Demographers often break these down further, such as the ratio of men to women and the life expectancy of each gender. In some studies, the research into an area is expanded to include education, income, the structure of the family unit, housing, race or ethnicity and religion.
Generally, there are two major strategies used to get information in demography. The direct method tries to connect with each person in a population, and the facts collected come primarily from vital statistics registries and censuses. The indirect method uses responses from only a segment of the population to get data about the entire group. This is a more common technique in countries that are still developing, because these regions often lack the organization and resources to maintain records on everyone.
Within these two general categories, demographers have a variety of choices on how to get the data they need. Probably the two most common are surveys and forms. Researchers like these options because formally putting the investigation on paper ensures that all respondents are asked for the same information in the same way. It also can be both time- and cost-efficient, and it allows people to store records and review them at a later time. Depending on the circumstances, however, a person also might use methods such as conducting interviews and making first-person observations.
People apply demography in many different contexts and industries. Governments, for instance, use it for political observations, or to determine a need for world assistance due to famine, disease or other issues. Scientists and scholars use it for research purposes, and in real estate, sales agents employ demography to give clients an overview of specific neighborhoods. Advertising relies heavily on this type of data, because companies need to be specific about trends to reach the maximum number of potential customers in their target audience. Similarly, education uses demography to help gather data to provide necessary governmental and local assistance. Additional areas of application include economics, which relates financial, social and political information, and sociology, which uses statistics to show how individual groups of people are organized and developing.
History and Evolution
Experts believe that people have practiced forms of demography for thousands of years. An often-used example is the ancient Roman census, which separated free men from slaves, gave Romans a sense of collectivity, allowed an estimation of tax revenue and contributed to military development. Through the Middle Ages and even the Renaissance, many kings and other political rulers used similar techniques to figure out how big their empires were, and to determine the potential threat of enemies.
Today, many of these purposes still apply, but a major difference is that advances in technology have dramatically reduced the amount of time and resources necessary to collect the information. This shift is arguably most noticeable starting in the second half of the 20th century, which saw the development of the computer. Contemporary demographers are able to collect data electronically through the Internet, and they also can keep digital records. People often can access these facts and statistics for free from the comfort of their homes, as well.