According to this story  in IHE, a retired Duke University professor named Stuart Rojstaczer has issued a study of grade inflation. His findings suggest that grade inflation is commonplace throughout higher ed, particularly at selective liberal arts colleges and at flagship public universities in the South, but is nearly unknown among community colleges.
The comments to the story are worth reading. Cliff Adelman suggests that Rojstaczer is not to be taken seriously. I tend to take Cliff Adelman very seriously, so I'm not going to endorse the findings of the study just yet.
Many of the other comments, though, are variations on “adjuncts are scared of bad student evaluations, so they inflate the grades.” I'm not convinced.
Selective liberal arts colleges tend to be expensive, and to have relatively low adjunct percentages. That's part of what they sell. Community colleges as a sector tend to have higher adjunct percentages than just about any other part of higher ed, yet the study singles them out as immune to grade inflation. If the study is correct, it pretty much blows the “scared adjuncts cause grade inflation” theory out of the water. The findings suggest that other variables – local culture, most likely – are far more powerful.
Anecdotally, at least, I'm inclined to support the 'local culture' theory over what I'll call Adjunct Determinism.
When I was at Proprietary U (the story doesn't mention whether Rojstaczer studied for-profits), grade inflation was rampant, and was almost official policy, but only on the low end. You could be as strict as you wanted with A's, but too many F's would get you fired. Although some of us objected strenuously to a fog-the-mirror standard for passing, when enrollments started to dip, it was made abundantly clear to the faculty that retention was to be pursued at almost all costs. Over time, naturally, students started to figure that out, with predictable results.
At Snooty Liberal Arts College, when I was a student, I don't recall too many people failing too many things. A's were tough, but B's were pretty common and D's or F's rare. And there was no such thing as an adjunct there.
At Flagship U, the TA's often graded much more demandingly than did the senior faculty. I interpreted that at the time as a form of insecurity on our parts. Frankly, I still do.
At my cc, I don't hear much talk of grade inflation, either from faculty or from students. (I hear plenty of complaints about other things – some valid, some not so much – but not about that.) That's not to say that we're unconcerned with student success – quite the opposite – but that we want that success to actually mean something. The adjunct percentage is far higher here than at SLAC or Flagship U, yet the grade inflation much less. That's why, despite my admiration for Cliff Adelman, at least this part of the findings sound right to me.
(On the flip side, the study singles out Princeton as having successfully attacked grade inflation. Did Princeton have a massive wave of adjuncts at some point?)
There are plenty of reasons to object to the adjunct trend, and plenty of reasons to object to grade inflation. But to assume that all bad things necessarily go together in a neat little package is a bit indulgent.
More likely, local expectations color grading, both for full-timers and for adjuncts. At the snootiest, high-end schools, where the adjunct trend is almost unknown, the culture of student entitlement is quite powerful. I haven't seen much of that at this level. If anything, the issue here is the opposite. Here, so many students come in with the emotional baggage of years of poor performance in the K-12 system that the challenge is in getting them to identify themselves as college material. At SLAC, getting a C was either an affront or a source of shame, depending on your mood; I've seen students here celebrate them.
I don't know if this study is actually valid or not, but it passes my gut test in a way that the 'scared adjuncts inflate grades' theory just doesn't. If Princeton has to issue a policy against grade inflation, but most community colleges don't, then I have a hard time pointing the finger at adjuncts. It's just not that simple.