The NIH policy change to allow multiple individuals to serve as the Principal Investigator (or Program Director for BigMech Awards) has been a whopping and unqualified success from my perspective. There are several situations that were addressed by this change, most importantly the extension of credit to a more-junior scientist. Since the PI reputation and track record was always such a big deal for the review of grants, it was often the case that the BiggestCheez was listed as the PI. Regardless of the amount of involvement of this individual. It was not rare to have very senior investigators allocating less than 10% effort as "PI" when another faculty member (perhaps even Associate Professor level) was allocating much more, say 15-30% effort, and clearly running the show for that particular project. For no official credit.
There was also a much harder to assess impact on collaborative science. In theory, there might be collaborative projects that did not get proposed precisely because neither partner was willing to do it without PI credit. Perhaps this resulted in the inefficiencies of two projects being funded when one would have sufficed? Perhaps it resulted in the collaboration never happening.
At any rate, I viewed the initial round of Multi-PI grants with interest. The first round or two featured a lot of discussion. Of the Leadership Plan. Of the need for a Multi-PI versus single PI application for that particular project. After that? Barely a peep. Nobody seemed to give it much thought at all. I've seen relatively recent summary statments where the fact that it is a MultiPI application is barely even discussed by the reviewers!
From my point of view this has become a non-issue for grant review and my advice, accordingly, is for people to go for it* if they think it fits their plans. I am curious as to whether my Readers have any experiences on either side of the review process to share?
The NIH, perhaps reacting to the reality that peer review panels don't give a hoot about Multi-PI leadership plans and rationales, has decided to let local institutions alter the Single/Multi designation of a project without competitive review. I will remind you that they already permit changes in the research team, including the PI, at the whim of the applicant institution (to whom the grant is actually awarded, of course). So this is not a major new step. Just an.....alignment of policies.
The recent Notice (NOT-OD-11-118) describes how the NIH will permit additional flexibility in the use of the Multi-PI/PD option.
After several years of experience with the multiple-PD/PI model, NIH has determined that there are legitimate circumstances under which it would be in the best interest of an active project to change either from a multiple-PD/PI model to a single-PD/PI model, or from a single-PD/PI model to a multiple-PD/PI model, and that peer review of the new leadership team and Leadership Plan may not be essential in these cases... a request to change an active award from a single-PD/PI to a multiple-PD/PI model, or from a multiple-PD/PI model to a single-PD/PI model, must be made by the grantee organization and should be based on the scientific needs of the project. Justifications based on administrative convenience will not be considered. If the arrangements proposed by the grantee, including the qualifications of any proposed replacement or addition, are not acceptable to the NIH awarding IC the grant may be suspended or terminated.
and since you will be wondering about the newbs...
A New Investigator who is added as a PD/PI on a substantial NIH independent research award after initial peer review will not lose their New Investigator status.
This latter makes for some very interesting grant strategy indeed. A noob could, in theory, be writing grants in collaboration with a more-senior PI to be submitted with that person as solo PI. With the understanding that if it gets funded, they will wait a year or two and then slip JuniorMint (who actually wrote the thing) into the Multi-PI slot. Then the Noob could be busily submitting her own ESI/NI qualified grants, all the while enjoying de facto major grant funding for which she will eventually get at least partial PI credit.
*I don't think this is a good idea for Noob Faculty before they've landed their first major award, however.