Population decline refers to a decrease in the number of individuals living in a specific geographic area. This decline can be caused by various factors such as low birth rates, high death rates, outmigration of residents, or a combination of these factors. Population decline can have significant social, economic, and environmental impacts on a community, including a shrinking workforce, reduced tax revenues, strained social services, and changes in the local culture and amenities. Researchers in this area may study the causes and consequences of population decline, as well as potential strategies for addressing and mitigating its effects.