Demography is the study of human population dynamics. Population is shaped by a number of factors including fertility, mortality, migration and urbanization. Significant demographic changes have been shown in many parts of the world. The world population growth has been decelerating since 1970s. Fertility rates in more developed countries (MDCs) have been showing a declining trend, whereas an increasing one in the less developed countries (LDCs). Mortality rates have gone down in both MDCs and LDCs due to medical advancement. Consequently, the population of the countries with low fertility rates aged more quickly, and the world population growth will be concentrated in those developing countries where fertility rates remain high. Uneven population growth among nations accelerated the migration of people across nation borders and the growth of cities. The changes of these interrelated factors with their causes and problems of each of the factors will be discussed, followed by some possible plans and opportunities that may benefit from these changes.Human birth rate (natality) is the fertility expressed as the average number of live births per thousand populations per year. Since not all age groups in a population have equal fertility, demographers often use more specialized measures of birth rates that relate to age groups.Human mortality rate is the average number of individuals who die per thousand populations per year.

Again, demographers often use more sensitive measures, for different mortality rates. Both the very young and the very old segments of the population have higher mortality rates than are found in other age groups.Human population shows uneven or clumping pattern of distri­bution on earth. The density of human population in a village, district, city, province, country or any area can be obtained by di­viding the total number of persons living in the given region by the total land area of that region.The average number of people per square unit of land area tells us how dense or sparse is the popu­lation in a giver, area. The average population density of the world is calculated about 27 persons per square agents to determine life insurance rates.

These early demographic studies were mostly concerned with mortality. However, in the 19th century, studies showed that there was a decline in the number of births, and researchers began to study fertility as well as mortality. These studies led to the idea of “differential fertility.” Differential fertility suggests that different groups within a population have different numbers of children due to factors, such as religion, cultural attitudes, poverty, and employment. Migration of people is the last main factor in demographic studies. It is these three variables (mortality, fertility, and migration) that contribute to population change.Demographers gather data mainly through government censuses and government registries of births and deaths. However, these sources can be inaccurate depending on the precision of government records. Demographers also gather data indirectly through surveying smaller groups within a population. These samples are then examined using statistical models to draw conclusions about the whole population.

Demography is changing us as we are older societies, we’re living longer. How the generations balance each other out, how that affects education and health care.