The threat of a brain drain of talented scientists to other countries is frequently used as a reason to support embryonic stem cell research. Now the leading journal Nature has made the counter- intuitive argument that source countries actually benefit from the flow of skilled individuals overseas. Take Britain. “According to the World Bank, Britain has more professional ?migr?s than any nation on Earth, but it doesn’t seem to be hurting. California’s research labs may be crawling with Brits, yet UK science has gone from strength to strength.”

What accounts for this phenomenon? First of all, scientists aspiring to go overseas work harder at home. When they leave, they also keep up their connections. In any case, stem cell research is just a minor feature of global talent flows. The issue is greatest in Africa. South Africa has even taken steps to penalise state-trained health professionals who leave. However, according to research from the Center for Global Development, in Washington DC, “impeding the migration of skilled health professionals, by sending and receiving countries, does little to improve health systems or heath outcomes in Africa.”