I also read an article on this a while ago that said that at least informally, the metrics changed in the IRS - the practice went from evaluating auditors based on the dollar value they recovered to evaluating auditors based on the number of files they opened and closed. So of course now the auditors focus on the small cases because they're quick and easy, and they don't want to have to explain to a performance management system why they closed fewer cases than their coworkers.