Population History 62 Fertility, Human 36 Economic conditions 34 Economic aspects 33 Demography 30 Birth control 27 more ... Population policy 24 Social conditions 18 Economic development 14 Environmental aspects 14 Population forecasting 12 Food supply 10 Migration, Internal 10 Overpopulation 10 Demographic transition 9 Emigration and immigration 9 Natural resources 9 Economic policy 8 Statistics 8 Human ecology 7 Periodicals 7 Mortality 6 Families 5 Social aspects 5 Age distribution (Demography) 4 Cities and towns 4 Colonies 4 Congresses 4 Government policy 4 less ...