Are invalid patents still cited?
Journal
Proceedings of the Association for Information Science and Technology
Journal Volume
56
Journal Issue
1
Pages
639-641
Date Issued
2019
Author(s)
Abstract
ABSTRACT Patents contain reference citations. However, unlike journal papers, patents may become invalid if they are not maintained or have expired. This study determines whether invalid patents are still cited. We collected telecommunications patents as a sample to compare the citations of valid and invalid patents. The results indicated that approximately 50% of cited patents were invalid. Furthermore, the citations per patent of invalid patents were fewer than those of valid ones. Nevertheless, the citations per patent of invalid patents were reduced 5.21, and nearly 5% of the patents were cited only after they became invalid.
Type
journal article