Miracle Vaccines. Videophones in our pockets. Reusable rockets. Our technological bounty and its related confusion with scientific progress seem undeniable and insurmountable. However, now analysts report that the overall pace of real progress has slowed dramatically over the past nearly three-quarters of a century.
In the journal Nature this month, the report’s researchers recounted how their survey of millions of scientific papers and patents shows that researchers and inventors have made relatively few breakthroughs and innovations compared to the world’s growing mountain of scientific and technological research. The three analysts found a steady drop from 1945 to 2010 in disruptive findings as part of the booming enterprise, suggesting that today’s scientists are more likely to advance incrementally than make intellectual leaps.
“We should be in a golden age of new discoveries and innovations,” said Michael Park, an author on the paper and a doctoral candidate in entrepreneurship and strategic management at the University of Minnesota.
The new finding by Park and his colleagues suggests that investments in science are trapped in a spiral of diminishing returns, and that, in some respects, quantity trumps quality. While not addressed in the study, he also raises questions about how far science can push new frontiers and sustain the kind of boldness that unlocked the atom and the universe, and what can be done to address the drift away from pioneering discovery. Previous studies have noted the slowdowns in scientific progress, but usually with less rigor.
Mr. Park, along with Russell J. Funk, also of the University of Minnesota, and Erin Leahey, a sociologist at the University of Arizona, based their study on an improved type of citation analysis that Dr. Funk helped devise. In general, citation analysis tracks how researchers cite the published work of others as a way to sort out the brilliant ideas from the less than exceptional in a flooded system of articles. His improved method broadens the analytical scope.
“It’s a very smart metric,” said Pierre Azoulay, a professor of technological innovation, entrepreneurship and strategic management at the Massachusetts Institute of Technology. “I was dizzy when I saw it. It’s like a new toy.”
Researchers have long sought objective ways to assess the state of science, which is seen as vital to economic growth, national pride and military strength. It became more difficult to do so as published articles increased in number to more than one million annually. Every day, that’s more than 3,000 documents, by any measure an indecipherable smear.
Defying the surge, experts have debated the value of incremental advances versus “Eureka!” moments that change everything known about a field.
The new study could deepen the debate. One surprise is that discoveries popularly hailed as groundbreaking are seen by the authors of the new study as little more than routine science, with true leaps sometimes missing from the conversation altogether.
For example, the top breakthrough on the study’s list of examples is a gene splicing breakthrough that is little known to popular science. It allowed foreign DNA to be inserted into human and animal cells instead of just bacteria. The New York Times referred to him in a four-paragraph 1983 story. Still, the feat produced a streak of awards for its authors and their institution, Columbia University, as well as for almost $1 billion in licensing fees as it boosted biotech operations around the world.
On the contrary, analysts would see two of the most celebrated finds of this century as triumphs of ordinary science rather than breakthrough leaps. The mRNA vaccines that successfully fight the coronavirus were based on decades of hard work without glamour, they noted.
So too, the observation of gravitational waves in 2015, subtle ripples in the fabric of space-time, was not an unexpected breakthrough, but rather the confirmation of a centuries-old theory that required decades of hard work, testing, and sensor development.
“Disruption is good,” said Dashun Wang, a Northwestern University scientist who used the new analytical technique in a 2019 study. “You want novelty. But you also want everyday science.”
The three analysts discovered the trend toward incremental advancement by using the enhanced form of citation analysis to analyze nearly 50 million articles and patents published between 1945 and 2010. They examined four categories: life sciences and biomedicine, physical sciences, technology, and social sciences, and found a steady drop in what they called “disturbing” findings. “Our results,” they wrote, “suggest that the decline in interruption rates may reflect a fundamental change in the nature of science and technology.”
His novel method, and citation analysis in general, draws analytical power from the requirement that scientists cite studies that helped shape their published findings. Beginning in the 1950s, analysts began to count those citations as a way to identify relevant research. It was some kind of scientific clap meter.
But the count could be misleading. Some authors cited their own research quite frequently. And science stars could get plenty of citations for unimportant finds. Worst of all, some of the most cited papers turned out to involve minuscule improvements on popular techniques widely used by the scientific community.
The new method analyzes citations in greater depth to separate the day-to-day work from the real breakthroughs more effectively. It counts citations not only from the research reviewed, but also from previous studies that it cites. It turns out that previous work is cited much more often if the finding is routine rather than innovative. The analytical method turns that difference into a new lens of the scientific enterprise.
The measure is called CD index according to its scale, which goes from the consolidation to the disruption of the existing body of knowledge.
Dr. Funk, who helped design the CD index, said the new study was so computationally intensive that the team sometimes used supercomputers to process the millions of data sets. “It took a month or so,” he said. “This kind of thing was not possible a decade ago. Only now is it within reach.”
The new technique has helped other researchers, such as Dr. Wang. In 2019, he and his colleagues reported that small teams are more innovative than large ones. The finding was timely because scientific teams over the decades have shifted their composition to ever-larger groups of collaborators.
In an interview, james a. evans, a sociologist at the University of Chicago who co-authored that paper with Dr. Wang, called the new method elegant. “Something important occurred to me,” he said. Its application to science as a whole, he added, suggests not only a falling return on investment, but also a growing need for policy reform.
“We have extremely neat science,” Dr. Evans said. “We bet with confidence where we invest our money. But we’re not betting on fundamentally new things that have the potential to be disruptive. This document suggests that we need a little less order and a little more chaos.