Leveraging patent citation data from the State Intellectual Property Office (SIPO) of China and Google Patents, we have constructed a patent citation network database at the national-firm dimension to measure the innovation network. A simplified schematic diagram of the patent citation network is presented below. 

The foundational patent data originate from the China Patent Database spanning 1985 to 2019, encompassing comprehensive information on all patents, including patent names, abstracts, categories, application numbers, application dates, publication numbers, publication dates, applicants, current patentees, inventors, and main classification codes. This foundational database comprises 4,915,331 invention patents.

Based on the patent publication numbers in the China Patent Database, we crawled the citation relationships of all invention patents from the Google Patent database, specifically retrieving information such as the publication numbers of patents citing the target patent. By filtering out patents not filed with the SIPO based on the format of the patent publication numbers, we ultimately obtained 16,484,092 invention patent citation pairs.

These patent citation pairs were imported into a connectivity table format, and an adjacency matrix of patent citations was constructed using the Python NetworkX package, resulting in a directed network of patent citations.

The following figure illustrates that during 1986-2000, the centrality of the patent innovation network experienced fluctuations with a relatively modest overall increase. Upon entering the 21st century, from 2000 to 2013, there was a substantial surge in the centrality of the patent innovation network, reflecting accelerated knowledge flow and the rapid ascendancy of the importance of certain patents. After 2013, however, the centrality of the patent innovation network exhibited a decline.

The lab has applied the Global Innovation Network and published 1 paper in Economic Research Journal:

Lyu Yue, Chen Yongchang, Zhang Haotian, Zhu Zhujun. E-commerce Platforms and Manufacturing Firm Innovation :On the Innovation-driven Path of Deep Integration ofthe Digital Economy and the Real Economy. Economic Research Journal. 2023, 8.