In a post published on Dynamic Ecology last week, Meghan Duffy presented a graph showing the number of authors of articles published in Ecology for the period 1956-2016. [SPOILER: it increases!]. She also noted that someone probably did something similar for the whole field of ecology but couldn’t find it. Neither could I.
I was thinking that it would take a lifetime to collect manually these data (even if I love to spend my time in the dirt of the lab library). But luckily I remembered that I kept a nice dataset of publication records for a good number of journals in ecology. Few years ago, my friend Ivan Mateus and I, scrapped these data to test some scientometric hypotheses. It took several months for us to collect these data, so I’m glad I have the opportunity to use it.
I was in a rush (at the airport on my way to the DNAqua-net kick-off conference) but the R code written 4 years ago to compile the data just worked perfectly! And I could quickly come up with a nice graph. I made some technical choices here: 1/ I deleted some outliers (some rare articles are featuring more than 100 authors!). 2/ I didn’t use a boxplot as Meghan did, because I had data for every year but also because the distribution becomes very skewed with time. 3/ I used a color scale to represent the number of papers, so points act like bins. I could use hexagonal bins to get a continuous surface, but I liked it with points. It just requires a manual tuning for the dot size.
The graph shows the number of authors of articles for 285951 articles published in 113 journals in ecology. It covers the period 1932-2012, but I suspect that data for many journals are missing before 1975. This can explain the sudden change in dots color.
In conclusion, I think this graph does a good job of showing both the increase in the number of paper published every year in our field and the increase in the number of authors per paper. I was expecting this trend but I was really surprised by its strength. And it looks like it’s not going to stop now.