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Scientists publish less than they used to (by some measures)

A fascinating study by Daniele Fanelli and Vincent Larivière was published yesterday in PLoS ONE. It's a bibilometric study (i.e. about how scientists publish their research), and its main conclusion is that scientists do not publish more than they used to—or at least not by all measures. This conclusion is surprising, because it goes against the cynical-but-widespread belief that scientists nowadays try to publish as many papers as possible, with little regard as to whether these papers contribute anything.

Let's start with a basic fact: For decades, and year after year, the total number of scientific publications has been increasing exponentially. You can clearly see this in the figure below, taken from one of my previous blog posts.

So what drives this growth? Multiple things, probably. To start with the obvious: The world's population has grown, and the number of scientists has grown even more rapidly (i.e. it has become more common to be a scientist); as a result, scientists are publishing more papers in total.

But many people would point out another important driver of this growth: the "publish or perish" culture.

Scientists are under a lot of pressure to publish papers—if you don't publish enough, you're out. This pressure is relatively new, or at least it seems to have increased over time; and it stands to reason that scientists would respond to this pressure by publishing more papers. For example, whereas a scientist in the eighties might have worked on a single, important paper for years, a scientist in the noughties would publish as soon as possible—lots of small, meaningless papers, instead of a single, important one. This belief is captured nicely by the following quote from the psychologist Roy Baumeister (taken from an interesting context):

“In the olden days there was a craft to running an experiment. You worked with people, and got them into the right psychological state and then measured the consequences. There’s a wish now to have everything be automated so it can be done quickly and easily online.”

Science used to be a craft that took time; nowadays it's all sloppy, quick, and dirty—or so the idea goes. But is this really true? According to Fanelli and Larivière it is not, or at least it is an exaggerated depiction of a more complex reality.

Fanelli and Larivière first noted that, indeed, scientists now publish about 50% more papers than they did in the eighties. However, the number of co-authors on these papers has increased as well—and even more so than the number of papers per author. In other words, the number of publications divided by the number of authors per publication has actually decreased a little bit. By this measure—and I would say this is a sensible measure—scientists aren't publishing more; instead, they are collaborating more, but publishing slightly less.

Fanelli and Larivière further looked at the number of first-author publications per scientist. Generally, the person that did most of the research appears as the first name on the paper. So, as a rule of thumb, the number of papers that a scientist actually wrote equals the number of first-author publications. And this measure has decreased too: In most fields, scientists now publish slightly fewer first-author papers than they used to.

So what does this mean? This is where we go from data to interpretation; and hence, this is where things get muddy and interesting.

One interpretation is that the main thing that has changed over time is the number of scientists, and how much these scientists collaborate. This would cause the total number of publications to increase, as well as the number of publications per scientist. But there seems to be no clear evidence that scientists publish their research more quickly and divided into byte-size bits; if anything, there is a tendency in the opposite direction.

Of course, the study of Fanelli and Larivière is just one analysis, and not the final word on the topic. But it makes one thing clear: If we're interested in the history of science, we shouldn't rely too much on our senior colleagues' gut feelings about the good old days; they will tell you that things were better, easier, and more fair. Such stories are interesting from a personal perspective, but if you want to know how science has actually evolved, a thorough bibliometric analysis is preferable.