There are more postdocs than faculty positions available in many countries.Credit: Lanshi Wu/Alamy
More than 40% of postdoctoral researchers leave academia, according to a study of some 45,500 researchers’ careers1. Those who stayed and landed a coveted faculty position were more likely to have had a highly cited paper, changed their research topic between their PhD and postdoc, or moved abroad after receiving their doctorate.
The study, published in Proceedings of the National Academy of Sciences on 20 January, looked at researchers around the world who had progressed from a PhD to a postdoc — a temporary position for further professional training, development and expanded research — and then, in some cases, on to a faculty position. The study covered 25 years and 19 academic disciplines and used data from Microsoft Academic Graph, a corpus containing 257 million publications. The researchers filtered the data using an online professional network (presumably LinkedIn, although the authors did not say) to match researcher’s curriculum vitaes.
Previous studies have focused mainly on how important the prestige of PhD-granting institutions is to landing a faculty job2. Bedoor AlShebli, a computational social scientist at New York University Abu Dhabi, United Arab Emirates, and her co-authors wanted to fill a gap in the research and quantify the significance of postdoctoral training to gaining a faculty position and early-career success.
“Our research highlights that the postdoctoral years are just as critical as the PhD years when evaluating a scientist’s likelihood of successfully entering academia and securing a faculty position,” she says.
A path to success
In many countries, there are more postdocs than faculty positions available. This creates a bottleneck. The team’s data set shows that 41% of postdocs end up leaving academia. AlShebli says that researchers who publish less during their postdoc than they did during their PhD are more likely to leave.
For researchers who stick around, what determines success? To answer that question the team developed a measure of scientific output — called the η-index — as a proxy for success. This measure is based on the h-index, a count of a researcher’s citations, but focuses only on papers published between two and four years after securing a faculty position.
