How Often Are Multiple WO Documents Found in the Same Extended Family?

One of the earliest articles posted, when this blog was relaunched at the beginning of 2013, was on how often multiple EP patents were found in the same INPADOC family. 60,000 granted EP patents where the United States was not listed as the priority country from 2006 were studied. Of these 60,000, only 15,147 of the Icases associated with these patents did not have a US  member in the INPADOC extended family. Granted EP patents without US family members, or US priority were chosen for analysis so the propensity for US documents to inflate extended families would not be a factor. Under these circumstances, only about 5% of the granted patents published in 2006 had more than one European application number in the extended family. In the previous post on this blog, a study of the impacts of PCT applications on US patenting was conducted. Since this was the case, it seemed reasonable to revisit the question of multiple documents, from the same authority, in extended families, but this time looking at WO documents. These analyses will inform additional thoughts on patent family reductions covered in the next post.

Following the same study protocol, and publication year, as performed previously with the EP study, 70,030 WO A1 documents published in 2006 without the United States as priority country were found. Once again, data was generated with Thomson Innovation so the most recent 60,000 of these documents were exported for further study. PCT applications with the A1 kind code were used to simplify the analysis. If A2 documents were used than the corresponding A3 documents, or lack thereof, would need to have been accounted for, when looking at the number of documents per extended family. Of these 60,000, 20,533 did not have a US document in the extended family. Within this collection, 97% or 19,846 documents, have a single WO document in the extended family. This is quite similar to what was seen in the case of European patents, and supports the idea that when US documents are not part of an extended family a one document per family (ODPF) approach to family reduction will produce a collection that closely represents the actual inventive output.

Previously, the circumstances where the US was not the priority country but there were US members of the extended family, and the cases where the US was the priority country, were not look at, but based on the close association between the US and WO systems, which were explored in the last post, it seemed like a good idea to look at these scenarios. Starting with the 39,467 WO A1 documents where the US was not the priority country, but there was at least one US document in the extended family, almost 93% or 36,551 have a single WO document in the extended family. This is a smaller percentage than what is seen when there are no US documents in the extended family. Looking a little more deeply at the collection of 39,467 documents, in 16,814 or in almost 43% of the cases the number of WO documents equaled the number of US documents in the extended family. In the remaining 57%, the number of US documents in the family was greater than the number of WO documents 96% of the time. Both of these observations begin to support the conclusion that when the US is involved family reduction using extended families will under represent the inventive output of the family.

In all the cases to this point, the applications are originating outside of the United States, what happens when the US is listed as the priority country? Staying in 2006 as the publication year, there were 24,219 documents where the US was listed as the priority country. This may seem small based on what was discussed in the previous post with regards to how many times the US was listed as the priority country, on PCT applications in this time frame, but keep in mind that during the same publication year there were also 34,627 WO A2 documents published, and these studies are focusing on the A1 documents to make the counting easier.

Of these 24,219 cases, 7.5% or 1828 of them do not have a US publication in their extended family. This is worth pausing on for a moment since it is the first time this situation has been examined. In these circumstances the US is the priority country, potentially arising from a provisional filing, but a US publication is never produced. There are a number of reasons why this could occur, but the one that seems most likely was alluded to in the previous post where it was suggested that some organizations might have used the PCT system as a means to delay publication in the US while the commercial implications of the invention were better understood, and the return on investment of filing a non-provisional application in the US were calculated. It would be reasonably easy to calculate this percentage over a longer time period to see if this rate changes over the years. In this case, it would be important to include the A2 documents, along with the A1s to get a complete picture. Stay tuned for a potential future post on this item.

In the 24,219 cases of A1 documents where the US is listed as the priority country, 80% or 19,478 of them have a single WO document in the extended family. This is a significant difference between when the US is not listed as the priority country, even when there is a US document in the extended family, where 97% and 93% are seen respectively. An even more dramatic difference is seen with the number of US documents found in the extended family for these collections where almost 64%, or 15,443 of the cases have more than one US member of the family. The chart below shows the distribution of US family members in the extended family for this collection:

The Number of WO Family Members is Subtracted from the Number of US Family Members and Distributed Across the Number of Occurrences

The Number of WO Family Members is Subtracted from the Number of US Family Members and Distributed Across the Number of Occurrences

When there are more than one US document in the extended family they have to be reconciled by application number in order to determine whether the additional documents represent unique applications, or if they correspond to pre-grant publications and the subsequent granted patents. 8,302 of the 15,443 cases have only two US documents in the extended family. These correspond to 16,476 unique documents representing 9,070 application numbers. It looks as if about 90% of these cases represent the situation where the pre-grant publication, and a corresponding granted patent are together in the extended family. The remaining 7,141 cases have three or more US family members and represent 25,120 unique application numbers. If we assume the majority of these represent more than one US application in the family, and we add the 800 multi-application cases from the instance where there were only two US documents in the extended family, it appears that some where around 33% or 8,000 of the cases involve multiple US application numbers in the extended family. Not to belabor the point, but clearly, in analyses where US documents are likely to be part of the collection being studied, family reduction using extended families would significantly under represent the number of applications that were filed for.

As was seen in the case of European patents, when US patent documents are taken out of the analysis, it is pretty rare to find extended families with more than one WO A1 document in it. The situation is likely similar for the A2/A3 document combinations keeping in mind that 67% of the time these documents will list the US as the priority country. The situation changes significantly when US documents find their way into the extended family. When this occurs there is a much higher likelihood that multiple WO A1 documents will be found in the extended family. This post also demonstrated how significant the issue of multiple-application number occurrences are with WO documents that list the US as the priority country.

Leave a Reply

Your email address will not be published. Required fields are marked *