Matt,
i once tried to do a similar study of IR/PR firms to see if there was an opportunity to trade them much like I wager horse races based upon certain jockey's instead of the horse.
My theory went, there must be some exceptionally good/effective IR companies out there who consistently through their promotional efforts are able to raise the share price of new clients in the very short term, and on a consistent basis.
(For example, every time a new OTC penny signs with IHUB-IR-INC. they experience a 25% gain within 30 days.)
Back in the penny stock heyday, I know newsletter touts were good for 50% of all volume, but I think most of the sheep have long been sheared.
I did manage to find a few that had about a 75% success rate of creating a small and consistent share price increase, but was unable to find any IR/pr who had results which were significant enough and consistent enough to develop a trade pattern on it.
In theory, it should exist.
Robert