University Official: At our on-campus hospital, insured students tend to have more procedures performed and longer stays than do uninsured students, even though uninsured students, on average, have slightly more serious medical problems at the time of admission to the hospital than insured students have. Critics of the hospital have concluded that the insured students are receiving excessive medical care. However, this conclusion is flawed. Careful investigation has recently shown two things: Uninsured students have much shorter stays in the hospital than is needed, and they tend to have fewer procedures performed than are medically needed. Therefore, excessive medical care is not a problem the university hospital faces.
In the university official's argument, the two boldface portions play which of the following roles?