Unit 2 Population Vocabulary Demography Arithmetic density Agricultural density Physiological density Ecumene Overpopulation Carrying capacity Dependency ratio Crude birth rate Crude death rate Total fertility rate Natural Increase rate Doubling Time Life expectancy Census Immigration Emigration Push factor Pull factor Distance decay Chain migration Step migration Intervening obstacles Refugee Transhumance Guest workers Endemic Infant mortality rate Intervening opportunity Intra-regional migration Inter-regional migration Pandemic Concentration Dependency ratio Epidemiology Medical revolution Industrial revolution Zero population growth Brain drain Quotas Key Concepts to Know 1. Definition of demography and importance of studying it