Fig 1. Patent records and the associated collaboration networks.

(a) Patent records contain collaborations at both the inventor and company levels. (b) By drawing a undirected link between nodes i and j if they filed a patent application at least once, we can construct the collaboration networks of inventors (or companies). The total times of collaborations between nodes i and j over the whole patent record is defined to be the weight of the link (i, j) (shown in black). The total number of collaborators of nodes i over the whole patent record is defined to be the weight of the node i (shown in pink). (c) The inventors (or companies) listed in each patent record forms a clique. For each patent, we calculated its repeat collaboration number (R _l) of its inventors (or companies) by averaging the accumulated number of collaborations among all the inventor (or company) pairs in the team (shown in black). The productivity of node i in a patent is defined to be the accumulated number of patents that node i has contributed. We calculated the team productivity (R _n) by averaging the productivity of all its nodes (shown in pink).