Collaboration Networks

Innovation rarely happens in isolation. Patents frequently list multiple assigneesassigneeThe entity (corporation, university, government, or individual) that owns the rights to a patent. or inventors from different organizations, revealing a rich tapestry of collaborative relationships. Network analysis uncovers the hidden structure of these connections -- which organizations co-patent together, which inventors form long-term collaborative teams, and how these networks have shaped the direction of technological progress.

When two or more organizations appear as assignees on the same patent, it signals a substantive collaborative relationship -- joint research ventures, licensing agreements, or cross-firm R&D partnerships. The network below maps these co-patenting relationships among organizations with significant collaboration ties.

The network exhibits a clear core-periphery structure. A dense core of highly connected major patent holders sits at the center, while specialized firms and research institutions occupy the periphery with fewer but often strategically important connections. This structure reflects the hierarchical nature of industrial R&D, where large firms anchor collaborative ecosystems.

Beyond organizational partnerships, individual inventors also form collaborative networks. When the same inventors repeatedly appear together on patents, it reveals stable research teams that persist across projects and years. These co-invention ties represent some of the most productive relationships in the innovation ecosystem.

Comparing the two networks reveals a fundamental asymmetry: organizational co-patenting networks are relatively dense and interconnected (many firms co-patent with many others), while inventor networks are sparser and more clustered (inventors tend to work within small, stable teams). This suggests that cross-firm collaboration is driven more by institutional partnerships than by individual inventor relationships.

International co-invention rates — the share of US patents with inventors from multiple countries — reveal the evolving geography of collaborative innovation. US-China co-invention grew steadily from near zero in the 1990s to a peak around 2017–2018, coinciding with trade tensions, entity list restrictions, and tightening export controls. The pattern is sharpest in semiconductors and AI.

When inventors file patents at different organizations over their careers, they create talent flowstalent flowThe movement of inventors between organizations, tracked by consecutive patent filings with different assignees. Net talent flow reveals which companies are gaining vs. losing inventive talent. that transfer knowledge between companies. The Sankey diagramSankey diagramA flow diagram where the width of links is proportional to the quantity of flow. Used here to visualize inventor talent flows between companies. below maps these inventor movements between major patent filers.

How similar are companies' patent portfolios? By computing cosine similaritycosine similarityA measure of similarity between two vectors based on the angle between them. Values range from 0 (completely different) to 1 (identical). Used to compare patent portfolio compositions between companies. between CPC subclass distributions and projecting with UMAPUMAPUniform Manifold Approximation and Projection — a dimensionality reduction technique that preserves both local and global structure, used to visualize high-dimensional data in 2D., we can visualize the competitive landscape of innovation.

Each company pursues a distinct innovation strategy that can be characterized across multiple dimensions. The radar chartradar chartA multi-dimensional chart that plots values along multiple axes radiating from a center point. Useful for comparing strategy profiles across several dimensions simultaneously. below compares strategy profiles across 8 dimensions for the most prolific patent filers.

How quickly do different companies move from application to patent grantgrant lagThe time (usually in days or years) between a patent application filing date and the date the patent is granted. Also called patent pendency.? Innovation speed varies dramatically across firms, reflecting both technology complexity and patent prosecution strategy.