The retention of US science, technology, engineering and maths (STEM) students is strong except among the best performers, says a study that followed student cohorts from high-school graduation as early the 1970s through to mid-career as late as 2005. The report, called Steady as She Goes?, debunks the notion that the United States is not producing enough STEM college graduates, say its authors. But it suggests that many high performers left in early to mid-career in the late 1990s. The authors, Hal Salzman of Rutgers University in New Jersey and Lindsay Lowell of Georgetown University in Washington DC, speculate that they may have opted for non-traditional science careers or higher-paying jobs.