Immigration from poor to wealthy countries:  experience of the United States.
D000569:Americas; D003710:Demography; D019049:Developed Countries; D004467:Economics; D004641:Emigration and Immigration; D004651:Employment; D005006:Ethnicity; D006280:Health Workforce; D009656:North America; D011153:Population; D011154:Population Characteristics; D011157:Population Dynamics; D011203:Poverty; D012923:Social Class; D012959:Socioeconomic Factors; D014171:Transients and Migrants; D014481:United States
Americas; Demographic Factors; Developed Countries; Economic Factors; Employment Status; Human Resources; International Migration; Labor Force; Low Income Population; Migrants; Migration; Nationality; Native-born; North America; Northern America; Population; Population Characteristics; Population Dynamics; Social Class; Socioeconomic Factors; Socioeconomic Status; United States