The statistics available to the admins don't give this information in any easily accessible form that I've found. There are statistics concerning what would seem clearly negative behavioral attributes (Members most on Ignore, Members most Reporting/Reported Upon, etc.), but I feel a lack of data to balance that.
Something that gives me* a percentage or simple numerical breakdown of where a member participates within the various areas of the forum would be grand in allowing me to gauge if the member's "value-added" outweighs their contentiousness when aiding the mod team with these decisions.
*ETA: And preferably accessible to the mods as something in-line rather than within the Admin CP.