Population and the invisible hand.
D003710:Demography; D005298:Fertility; D049671:History, 18th Century; D049672:History, 19th Century; D049673:History, 20th Century; D006801:Humans; D011153:Population; D011155:Population Control; D011157:Population Dynamics; D011158:Population Growth; D012924:Social Conditions / Q000266:history