The Population Association of America and Association of Population Centers are two affiliated organizations that represent over 3,000 population scientists—including demographers, economists, sociologists and statisticians—and more than 40 federally-funded population research centers nationwide. Population scientists conduct scientific research on population trends and the individual, societal and environmental implications of population change. Their research expertise covers a wide range of issues, including, but not limited to: adolescent health and development, aging, health disparities, immigration and migration, marriage and divorce, education, social networks, housing, retirement, and labor.#fact-sheet