Continuing Patent Applications at the USPTO

Despite their growing importance for firm innovation strategy and frequent appearance in U.S. patent policy debates, how continuing patent applications are used remains unclear. Turn-of-the-century reforms strongly limited opportunities to extend patent term and surprise competitors, but continuing applications have steadily risen since. We argue that they retain a subtle use, as applicants can file continuations to keep prosecution open and change patent scope after locking in gains with the initial patent. We document a sharp drop in parent abandonment and rise in continuations per original patent after the reforms. Continuing applications are more privately valuable than original patents, are filed in more uncertain contexts, for higher value technologies, by more strategic applicants, and react strongly to the notice of allowance. The evidence supports a current strategic use of continuing applications to craft claims over time.