Using USPTO bulk data for patents granted between 1976 and Jan 9, 2018, I extracted each patent’s earliest priority date and then used those dates to calculate:
- average time between earliest priority date and filing or 371 date for: (1) all patents, (2) continuations, and (3) PTAB-challenged patents
- percent of all patents and of PTAB-challenged patents that are continuations ( NOTE: For simplicity I am using “continuation” for any patent having at least one continuation, continuation-in-part, or divisional in its lineage.)
Time from Earliest Priority Date to Filing/371 Date
The figure below shows the average and median time from earliest priority date to filing/371 date for all patents, continuations, and PTAB-challenged patens. (NOTE: for simplicity, “continuations” here refers to any patent having a continuation, continuation-in-part, or divisional in its lineage). Between 1996 and 2011 the amount of time between the earliest priority date and the filing/371 date grew roughly linearly across all patents (orange line), and roughly exponentially for continuations (blue line). Then, around 2011 it seems to have leveled out across all patents and even started declining for continuations. If anyone has any theories as to what happend around 2011 to reverse the trend changed, I would love to hear them. As for patents challenged at the PTAB, you can see that the time from earliest priority date to filing/371 is much larger than the typical patent.
Percent of Patents That Are Continuations
The next figure shows the total number of patents in the dataset broken down by continuations and non-continuations. Hovering over the bars gives the numerical percentage of continuations for each year. That number has grown from a post-GATT/TRIPS low of ~17% in 1998 to ~27% in 2012 and 2013. (Note: this data seems to agree well with similar metrics provided for all applications (not just issued patents) in this post on PatentlyO).
Percent of PTAB-Challenged Patents That Are Continuations
The final figure below shows the total number of PTAB-Challenged patents in the dataset broken down by continuations and non-continuations. The percentage of PTAB-challenged patents that are continuations is much higher than the general population of patents. In fact, PTAB-Challenged patents with a filing/371 date after 2014 are almost all continuations.