Should NIH limit the number of simultaneously held research grants?

NIH has posted a new Request for Information notice that suggests limiting the number of research project grants (RPGs) that an individual investigator can hold simultaneously.  The intention is reasonable–to allow a larger number of researchers the opportunity to pursue their research ideas.  The suggested limits are 2, 3, or 4.  It is important to note that the proposal does not indicate exceptions for small grants or multiple PI grants. Researchers’ feedback on this proposal seems to be mixed, so if you want to share your thoughts, submit your feedback before August 4!.