Introduction: The international mobility of talent and innovation. New evidence and policy implications

At the time of the French Revolution, the United States was the world's biggest exporter of cotton but did not possess appropriate technology - such as water spinning frames - to process it. Such technology existed in Great Britain. Aware of this technological advantage, the British authorities banned textile craftsmen from traveling to the United States. Nonetheless, in 1789, a twenty-one-year old Derbyshire-born apprentice of the early English textile industry, Samuel Slater, could not resist offers from American entrepreneurs and emigrated, bringing textile technology to the United States. Known as "Slater the Traitor" in Britain, he became the "Father of the American Industrial Revolution." In the United States, he partnered with industrialist Moses Brown, who had acquired a spindle frame but was unable to operate it. Slater used his knowledge to adapt the technology to local needs - one of the many factors that spurred American industrial development, for the United States to eventually overtake Britain as the world's leading industrial nation. Interestingly, Slater's wife, Hannah, invented a type of cotton sewing thread and became the first American woman to be granted a patent in 1793. Moreover, Slater's brother John, a wheelwright, spent time studying Britain's latest technologies and emigrated to the United States in 1799 to join his brother in the emerging American textile industry. This rich anecdote illustrates the important contributions migrating knowledge workers have made to the diffusion of knowledge and subsequent technological development in their adopted home countries. These contributions are no less important today. Take the case of Professor Venkatraman Ramakrishnan, who received the 2009 Nobel Prize in Chemistry for studies of the structure and function of the ribosome. Professor Ramakrishnan was born in India and studied at Ohio University. When he received his Nobel Prize, he worked at the Laboratory of Molecular Biology of Cambridge in the United Kingdom. Like many of his fellow Nobel Laureates, Professor Ramakrishnan has been a prolific inventor, applying for numerous patents. He has also reinforced his ties with his homeland and regularly visits Bangalore, where he "works on papers and reviews, gives lectures and talks to colleagues and especially young scientists there.".