Submarine Patents from a 21st Century Vantage Point: Honors Thesis Proposal

I am writing an interdisciplinary senior thesis at Brown spanning the fields of computer science and economics. The subject is submarine patents.

A submarine patent is a patent whose prosecution review at the US Patent & Trademark Office is purposefully prolonged by the applicant, in the hopes of “emerging” some years later with a patent on what has become a fundamental technology, extracting licensing fees from businesses who have already built upon this technology without knowledge of the patent’s filing.

Two reforms made submarine patents much less worthwhile to pursue. While patent terms used to be determined from issue date, starting in June of 1995, all new patent filings would receive terms from date of filing — the fact that the clock was ticking during prosecution made stalling at this stage much less desirable. A further reform came in November of 2000, when the USPTO announced that most patent applications would be published to the world 18 months after filing. Given the changes in patent term structure and the lifting of the veil of secrecy surrounding patent applications, the ability for inventors to unexpectedly corner a market long after filing their invention has been effectively eliminated.

Despite the closure of these loopholes, submarine patents continue to issue. In examining all patents that have issued over the past several decades, a single anomaly is prominent: many applications self-sorted to file prior to the closing of the loophole. A tremendous number of patent applications were filed in these days and weeks, and we now see that these were no ordinary applications. In fact, applications filed in these few weeks represent the most pronounced spike in average pendency in modern history. Identifying submarine patents as those filing prior to this discontinuity offers a unique vantage point from which to study the motives for and outcomes of submarine patents.

First, I have downloaded the full text of every patent granted in the past three decades.

I transformed these documents into roughly the following relations (number of tuples in parentheses):

  • Basic bibliographic info — one line for each patent grant (4.8M) (dta sample)
  • Assignee: name, address, etc. (for all assignees of patent) (4.3M) (dta sample)
  • Inventor: name, address, etc. (for all assignees of patent) (11M) (dta sample)
  • References to other patents (in the US and abroad) (55M) (dta sample)
  • References to “non-patent literature” (papers, brochures, etc.) (16M) (dta sample)
  • Parents (1.8M) (dta sample)
  • Fields searched by examiner as prior arts (11M) (dta sample)

Presentation to Brown’s Economics Honors Thesis Class Nov. 20, 2012 (PDF):