Continued growth in the number of inventors per patent.

by Dennis Crouch

I created the chart above using files from recently published US patent applications. The chart shows the average number of inventors per published application. I have been awaiting the 3.0 inventors-per-patent threshold for a while, and that has now been crossed.  The average (and median) patent application publication now lists three or more inventors.  In general, there are fewer patent applications then ever that list only one inventor. The number of 2-inventor applications has also fallen, but not as dramatically.

Averages can be shifted by extreme outliers. In our sample there are a small number of applications with a large number of listed inventors.  Example, Ericsson’s Pub. Nos. 20200028745 and 20170331670 that each list 133 inventors haling from Sweden, Finland, Germany, USA, China, and Korea.

18 thoughts on “Continued growth in the number of inventors per patent.

  1. 4

    Taking your results at face value — that there are no major changes from Jan 2013 to date which would affect the number of inventors per patent, and that on average the number of inventors per patent is increasing — How does this break down by technology? For example, do biotech patents typically have more inventors than automobile carburetor patents?

  2. 3

    Employee-inventor programs within companies and organizations (offering a monetary award to each inventor upon allowance), do impact the number of inventors on patents. Programs that give the same monetary award to each inventor, regardless of the number of inventors, obviously foster an incentive for over-inclusion. I’ve seen cases where employees had unspoken but understood pacts (“name me on your applications and I’ll name you on mine”), and these programs encourage supervisors and managers to insist upon being named on patent applications even if they had no actual involvement in the underlying project. All of this results in people being listed who do not qualify as “inventors,” even under a conservative approach. This is compounded by the fact that over-inclusion is often viewed as a victimless practice, as the impact of paying additional inventor awards is usually not economically material to the company as a whole. It’s also almost impossible to detect; over-inclusion only really gets uncovered through inventor depositions, which are rare as the overwhelming majority of patents will never see any kind of litigation.

    Of course, these incentives flow the opposite direction for inventor programs that provide a fixed award per-patent that is split among named inventors. Because more inventors means a reduced award for each inventor, this type of program creates an obvious incentive for under-inclusion. This is an outcome that, a number of companies have understandably concluded, is worse than over-inclusion.

  3. 2

    The “band” per “by publication date” seems to be extremely wide (greater than 5%, approaching 10% on a normalized basis).

    I wonder what would cause such noise.

    1. 1.1

      Just the results of a large project that got bounced from team to team or a very large project no doubt. Guess you guys saw the paper from the google team that was supposedly “ground breaking” in the quantum computing world. Had like 90+ authors and wasn’t that large of a paper. Obv the team required was gigantic.

    2. 1.2

      Over-inclusion is always better. Can be corrected during litigation (which is only where inventorship issues arise). See Dana-Farber inventorship litigation, Dana-Farber Cancer Institution Inc. v. Ono Pharmaceutical Co.

      Most employers offer rewards/incentive to scientists (and some national laws also require inventor remuneration) when they are named as an inventor. For the U.S., it is typically part of a MIP goal for a scientist. When there is grey area about who contributed what, and the claims are sufficiently broad to cover all aspects of the invention disclosed in the spec, IP practitioners will err on the side of inventor “over-inclusion” because they don’t want to be the person who denies the scientist a MIP goal. Such is life.

      1. 1.2.1

        xtian, you might be interested in the sad tales of woe that US industry can relate, of over-naming inventors in those jurisdictions (including Germany and Japan) where the law prescribes compensation for inventions made by employees within that juridiction. When the invention turns out to be, years later, the foundation of their business, but then the employer “lets go” the named inventor, and the inventor isn’t overjoyed by that, the financial consequences can be startling.

        Today’s newspapers here in Munich report that Apple will spend a nine figure sum over the next 5 years to set up its “Research Centre” here. But its in-house patent people will surely be aware of German law on inventions made by employees.


          … sad tales of woe – of overnaming?

          Besides the potential of increased (immediate) Award payouts, did you have other woes in mind?

          (Genuinely curious)


            Woes? Not really. But another possible booby trap is that outside the USA striking out a co-inventor that you want now to de-name can be problematic (in that one needs the signature of the inventor to be deleted), whereas no signature at all is needed, if one is to be added. Within the USA it’s the other way around, is it not?

            So when you want to err on the side of caution, what do you do? Over-name or under-name?


              I find it a curious policy decision that a scientist who is mis-named (the terminlogy used by the MPEP) can only be removed if the inventor him/herself signs off. Doesn’t that mean that inventorship is a determination by scientists, not registered patent attorneys/agents?



                I think it to be a bit more nuanced (on both ends).

                On the putative inventor side, my take is that the law is so as a protective measure in view of the otherwise imbalance of power between a corporation and any particular individual.

                On the “scriviner” side, while a is indeed true that the registered patent attorney/agent determines the form of the claim, and thereby captures the substance – to which substance any actual inventors are mapped to for their individual contributions, in practice, there is almost never a ‘clean’ or clear mapping of contributor to feature, and it is NOT typically in the purview of the attorney/agent to suss out such mapping.


          Yes to both xtian’s over-naming of inventors incentives and Max’s foreign inventor compensation law consequences. Also, in the U.S., naming a non-employee as a joint inventor can lead to the far more serious consequences of unrestricted joint ownership of the entire patent. Filing divisionals with the same joint inventor list, or extensive claim amendments in prosecution, with different claims, can presents other issues that may be raised via depositions when the patent is litigated. Anon’s point that “in practice, there is almost never a ‘clean’ or clear mapping of contributor to feature, and it is NOT typically in the purview of the attorney/agent to suss out such mapping.” can be more bluntly expressed as the fact that clients are rarely willing to pay their application preparation attorneys for the extensive extra time that would be required for fully investigating the inventorship contributions to each claim where the invention disclosure lists plural names.

                1. Yuk. Yuk. I believe he’s wondering how there can be . . . 8 10ths of an inventor.

                  Oh, look. It’s Friday. Yea.

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