Jones, along with Northwestern colleagues Stefan Wuchty and Brian Uzzi, has quantified this change. In a paper published in Science in 2007, they looked at 19.9 million papers and 2.1 million patents since 1955 and found that the average number of authors per paper has nearly doubled, from 1.9 to 3.5; the number of inventors per patent has increased from 1.7 to 2.3.
“Your probability of writing a home-run paper as a solo author has declined dramatically,” Jones says. Perhaps surprisingly, the same trend is seen in the social sciences, where 52 percent of papers are written in teams–up from 18 percent in 1955. “The fact that we see the same pattern everywhere suggests it’s the human capital that matters most,” Jones adds. Nothing is more valuable than the accretion of knowledge, but now it takes more people to produce it.
It also takes scientists more time to acquire the knowledge expected of them before they are granted full professional status. In a 2008 paper, “The Burden of Knowledge and the ‘Death of the Renaissance Man,’ ” Jones observed that the age of scientists receiving PhDs rose across all major fields starting in the late 1960s; the duration of a PhD program in the life sciences has also expanded since the 1960s; and today’s Nobel Prize winners received their PhDs substantially later than those who received the awards in the early 20th century.
It may even be that science is now demanding too much of students before stamping them with PhDs, preventing talented young researchers from making breakthroughs or setting the research agendas for their own labs. “In medical research, there is a palpable sense that people are being delayed before getting the chance to do research,” says Jones. Indeed, Elias Zerhouni, director of the NIH from 2002 to 2008, has called this the most important challenge facing the federal funding agencies.
A quixotic quest?
Despite the progress they have made in establishing a new area of research, economists who study the scientific enterprise increasingly find themselves preoccupied with a new problem: getting people outside economics, and inside science, to look at–and act on–their findings. Executives at the NIH and NSF generally embrace economic studies. But active scientists, as Azoulay points out, tend to be too focused on their own research to imbibe the social-science literature. “If we do our job correctly, we’ll convince scientists and scientific leaders they should build these kinds of evaluations into their projects,” he says. “But we’re not there yet.”
Jones agrees. “The agencies are actually quite receptive to evidence,” he says. “But the scientific community hasn’t fully absorbed these findings yet.” Murray says it has been “a hard struggle to convince people that studying science and scientists is a valid activity and that the social sciences have something useful to say.”