One in ten students at the master's or equivalent level is an international student within the OECD, and one in four at the doctoral or equivalent level. International doctoral students tend to choose countries investing substantial resources on research and development (R&D) in tertiary educational institutions. This offers these countries a channel to attract future workers with advanced training, particularly in science and technology; in several OECD countries more than half of those enrolled in a doctoral programme in science, engineering or agriculture are international students.