Continuing Patent Applications at the USPTO

Abstract

Continuing patent applications (continuations, continuations-in-part, and divisionals) are important for patenting strategies and a frequent topic in patent policy debates in the United States. However, there is little research on their use. We analyze recent trends in continuing application filings and examine who uses them, for what technologies, and their relationship with events in patent examination. We find that applicants are increasingly using continuations to modify patent scope after the issuance of a first patent and that the use of continuing applications is associated with measures of patent private value. Continuing applications are used more often for technologies with long lags between invention and commercialization (e.g. in biotechnology and for inventions that build upon science). Continuations are also frequently used in computers and communications and by patent assertion entities. There is no strong association between change in patent scope during examination and continuing applications. Our results suggest continuing applications are mainly used to change patent scope over time rather than to respond to rejections or to react to claim narrowing during examination.