GAO already does a lot of case studies-or at least, what we ourselves call case studies in describing our methods.
GAO is currently trying to limit the number of case studies it does because of the drain on resources. 
mnli hypothesis: GAO is currently trying to limit the number of case studies it does because of the drain on resources.  premise: GAO already does a lot of case studies-or at least, what we ourselves call case studies in describing our methods.