Similar methodologies: stock of foreign born residents in OECD countries in given years (1990 and 2000 for DM06; 2000 and 2005/6 for DIOC), disaggregated by: migrants' origin country age class gender 3 levels of educational attainment PLUS figures on the number of residents in origin countries Sources: census data or labour force surveys  total emigration from any single origin country: f_stock j =  i f_stock ij  foreign born residents in any destination country i: f_stock i =  j f_stock ij BrainDrain j = hsf_stock j /(hsf_stock j +hs_residents j ) BrainIntake i = hs_stock i /hs_residents i
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