When deaths exceed births:  natural decrease in the United States.
"This article delineates the incidence and regional variation [in the United States] of natural decrease since 1950, considers the demographic factors that caused natural decrease, assesses each factor's relative impact, identifies shared characteristics of areas experiencing natural decrease, and considers the implications of natural decrease." Factors considered include shifts in the age structure, fertility declines, increases in mortality, and migration.
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D017677:Age Distribution; D000367:Age Factors; D000569:Americas; D001723:Birth Rate; D003710:Demography; D019049:Developed Countries; D004641:Emigration and Immigration; D005298:Fertility; D005843:Geography; D009026:Mortality; D009656:North America; D011153:Population; D011154:Population Characteristics; D011157:Population Dynamics; D012106:Research; D014481:United States
Age Distribution--changes; Age Factors; Americas; Comparative Studies; Demographic Factors; Developed Countries; Fertility; Fertility Decline; Geographic Factors; Migration; Mortality; North America; Northern America; Population; Population Characteristics; Population Dynamics; Research Methodology; Spatial Distribution--changes; Studies; United States