Emigration and immigration Immigrants 19 Social aspects 19 History 16 Economic aspects 13 Government policy 13 Social conditions 11 Globalization 8 Illegal aliens 6 Social sciences 6 Asians 5 Businessmen 5 China 5 Entrepreneurship 5 Foreign workers 5 Singapore 5 United States 5 Asia 4 Brain drain 4 Crime 4 Economic conditions 4 Education 4 International cooperation 4 Multicultural education 4 Population 4 Alien labor 3 Boundaries 3 Chinese 3 Demography 3 Ethnic relations 3