Over the past few years there have been periodic bouts of speculation and controversy over the extent of South Africa's brain drain. Statistics South Africa stopped collecting data on emigration several years ago, and the flawed conduct of the 1996 and 2001 censuses has left question marks hanging over calculations based on other official data.
In 2006 the South African Institute of Race Relations estimated - by comparing the figures in Stats SA household surveys from 1995 and 2005 (as well as analysing other data) - that 841 000 white South Africans had left the country in that period.
However, as Patrick Laurence pointed out at the time there had been a considerable undercount of whites in the 2001 census and as a result the whites "who ‘disappeared' between 1995 and 2005 may not have emigrated. They may simply not have been counted in the 2001 census and consequently may not have been reflected adequately, if at all, in subsequent statistical data released by Stats SA."
Laurence further quoted Hilary Southall, a member of the Statistics Council, as saying that if the SAIRR had used the 1996 household survey figure as its starting point - rather than the 1995 one - the decline in the white population would have been measured at 127 000.
As it happens the main destination countries of South African emigrants do keep figures on the foreign born population of their countries. From this data, which is available on the OECD website, it is possible to get a fairly good idea of the extent of South African emigration.
19 OECD countries keep this sort of data. As the table below indicates - in 2010 - at least 588 388 individuals in these countries were recorded as having been born in South Africa. The real figure is likely to be higher than that as the figures for Canada and New Zealand date from 2006 and since then there have been further documented inflows of South African born migrants.