Demographic changes are the dynamics in the quantifiable statistics of a given population. Demography seeks to understand population changes by investigating such demographic components as gender, age, ethnicity, home ownership, mobility, disabilities, language knowledge, employment status and location. These elements and how they change constitute vital information about the population of a given location and its culture.
Demography examines the relationship of changes through deaths, births and migration in demographic composition, with the natural environment and with social and economic change. Demographic indicators may include population size, crude birth rate, population growth rate, crude death rate, fertility rate, life expectancy and infant mortality. Estimated and projected gender and age distributions in relation to fertility rates could also be included. The impact of demographic change is considered as one of the most important challenges for the future.
Demographic changes influence all aspects of human activity, including economic, social, political and cultural. For instance, the age distribution of a population has an overwhelming influence on health-care needs. This is especially recognized in the U.K., where allocation of NHS resources is based on the age-weighted capitation. At the local level, demand for health-care services may even be more age based than what is allowed by the national capitation formula, where the elderly are more likely to be admitted and for longer days of stay. An aging population is more likely to put considerable pressure on public spending programs, such as health-care and pension plans.