The US higher-education system tops a list of 48 countries in a ranking released on 10 May. Authors compiled the list from data on resources, output, connectivity and environment for Universitas 21, an international network of research universities based in Birmingham, UK. Co-author Ross Williams, professorial fellow at the Melbourne Institute of Applied Economic and Social Research in Australia, says that the list can guide early-career researchers to the higher-ranking nations that are more likely to provide the funding, positive environment and peer interaction needed for career advancement.