Fig. 3
From: Health policy and systems research collaboration pathways: lessons from a network science analysis
The structure of health policy and systems research co-authorship network from 1990 to 2009 (left panel) and 1990 to 2015 (right panel). Node colour represents first-authors’ economic region. Compared with the previous figures, the size, connectivity and robustness of the large connected component (LCC) grows over time. From 1990 to 2009 (left panel) 4375 nodes (65%) contribute to the formation of SDCs and 2394 nodes (35%) belong to the LCC, while during 1990–2015 (right panel) these are 6078 (39%) and 9623 (61%), respectively. Orange colour indicates low-income countries (LICs), green for lower middle-income countries (LowerMICs), pink for upper middle-income countries (UpperMICs) and blue for high-income countries (HICs)