Metropolitan migration efficiency.
D000328:Adult; D000367:Age Factors; D000368:Aged; D004522:Educational Status; D004526:Efficiency; D005006:Ethnicity; D005843:Geography; D006801:Humans; D007221:Industry; D009790:Occupations; D011157:Population Dynamics; D011158:Population Growth; D012044:Regression Analysis; D013223:Statistics as Topic; D014481:United States; D014505:Urban Population; D014507:Urbanization