Nate - I'd definitely be very interested in helping with this type of whitepaper! I won't have any time until after April (3 events between now and then, and likely over 11,000 photos to process!), but I'd be happy to jump in and help after that if that would be useful.
Just anecdotally, a great area to study would be the start up of Regional events. I know there were at least 7 rookies started the first year of the Finger Lakes Event and as far as I can remember, all 7 are still competing today (one took a year off I believe). I don't know if that comes from the strength of the Rochester community, or the founding of the local Regional and support from the committee. But I know some of those teams were organic (ie not started by the committee) but others may have been encouraged by the committee. So I'd love to help dig up some of those "pockets" or "bursts" of teams that survived. I also know that in Mass an influx of sponsorship caused a TON of Rookies to be started several years ago, and so many of them died off mostly because of lack of mentors.
Ultimately, I think the biggest question that you/we are alluding to is
How do we create and RETAIN more Rookies? Right??
