Fig. 5

In a, b, we display the communities found in the global collaboration network constructed from data between 1970–1974 and 2015–2018 respectively, using \(\tau =1/\gamma =0.76\). We can observe for instance that in 2015, Europe in particular appears highly (sub-)regional, and much of Oceania becomes its own separate community at this finer scale. c, d Show communities in these same periods, coloured as in the Sankey plot in f below, but found instead with \(\tau =1.0\). We observe that while in 1970 these communities were globally distributed (in some cases along colonial lines), in 2015 they appear to overall be more regionally focused. This is supported by e, where communities are connected between adjacent periods if their Jaccard (similarity) index is greater than 0.6. f Compares the community structure of adjacent time periods using the NMI, showing generally increasing stability of the community structure over time. g Compares each partition to a partition where nodes are split into continents, highlighting the increasing similarity of the communities to continents over time. Finally, h displays the ratio of the stability of each partition to the continental partition, with the dashed red line at 1 thus corresponding to equal stability, further supporting the latter insight. For each of f, g, h, results for communities found with \(\tau =1.0\) are shown solid, and dashed for \(\tau =0.76\)