I was reading through Paula Stephan’s How Economics Shapes Science – which is, by the way, an utterly fantastic book for anyone who wants to understand how universities actually work – when I came across this interesting little table.

Average Number of Co-authors per Paper

Over the space of nearly 20 years, the average number of co-authors per article has increased across all fields of study, albeit not uniformly (the effect seems bigger in the physical sciences). But why is this happening exactly?

Improvements in IT are one possible answer. A cynic might point to the increased importance of publication in the tenure process – more co-authors per article means less work per author, which in turn makes it possible for each individual scholar to produce more publications. A third answer is less cynical but perhaps more troubling: it may simply be that the overall productivity of academic researchers is declining.

We know that over the decades, the degree of researchers’ specialization has increased and the time to Ph.D. graduation has crept up. There’s simply an increasing amount of knowledge to be absorbed before one can be considered to be at the cutting edge. Newton famously said he stood on the shoulders of giants; these days, doctoral students have to clamber up a large pyramid of giants in order to get to the point where they can become fully-fledged members of the academy.

The trend to specialization is a way of dealing with this problem – it cuts the width (if not the depth) of what doctoral students need to know in order to be given their diploma. But since worthwhile – i.e., publishable – research usually crosses these sub-sub-sub-disciplinary boundaries, the trend to specialization has led to a decline in the ability of individual researchers to complete publishable research independently, and in turn requires increasingly large teams in order to obtain publishable results.

We can’t be completely sure about what’s going on because to my knowledge the necessary bibliometric studies haven’t been carried out. If the tendency for larger authorial teams is actually being offset by increased publications per professors, then there’s nothing to worry about because it implies that specialization is doing what Adam Smith and his pin factory said it would (that cynical explanation I provided earlier? It’s actually the hopeful scenario).

If, on the other hand, the number of publications per professor is not increasing as fast as the number of authors per paper, then we may really be hitting some kind of productivity wall. And that’s probably not good over the long-term for the logic underlying both the modern research university and graduate education as a whole.