Economic conditions -- Social conditions -- Politics and government -- 7 Foreign relations -- 3 Social indicators -- 3 Social prediction -- 3 Relations -- 2 more ... Statistics 2 21st century 1 Civilization -- 1 Congresses 1 Congresses -- 1 Economic conditions 1 Equality -- 1 Forecasts 1 Income distribution -- 1 Military policy -- 1 National characteristics, American 1 National security -- 1 Public opinion -- 1 Social aspects -- 1 Social conditions 1 Twentieth century -- 1 less ...