Patenting Inventions or Inventing Patents? Strategic Use of Continuations at the USPTO

Continuations allow inventors to add new claims to old patents, leading to concerns about inadvertent infringement and holdup. We study the use of continuations to obtain standard essential patents (SEPs), a setting where patents are easily linked to possibly infringing technology. Continuation filings increase after standard publication. This effect is larger when patent examiners are more lenient, and for applicants with licensing-based business models. Claims of SEPs also become more similar after standard publication, and late claiming is positively correlated with litigation. Our findings suggest widespread use of continuations to "invent patents" that are infringed by already-published standards.