A lot of pixels have been spent discussing this study of grade inflation, brought to most people’s attention via this New York Times blog. The key graph is this one, showing the fraction of grades given in each letter category over the last fifty years:

i-200956c5d1d57678d43343b1a029096b-economix-13gradeinflation-custom1.jpg

Lots of effort is being put into trying to explain why the number of A’s given out has increased so much over this time span, with most of it focussing on the last twenty years or so (see Mad Mike for a plausible but wrong explanation– the fraction of students going on to graduate school isn’t big enough to drive this). I think this is misguided, though, because it buys into one of the most pernicious myths about grade inflation, perpetuated by older professors: that grade inflation is something new, brought on by spineless younger faculty who can’t hold to high standards. The really important thing about this graph is that it ought to blow that theory out of the water.

If you look at the data, it’s abundantly clear that grade inflation is not a recent phenomenon. First and foremost, there’s that huge Vietnam-era lump, with the fraction of A’s given basically doubling between 1966 and 1974. Even before that, though, there’s a clear upward trend. In fact, if you use a piece of paper as a straight edge, you can see that the points from 1960-1966 fall on the same sloping line as the points from 1988-2008.

So if you want somebody to blame for grade inflation, blame the Baby Boomers. First, as students, they got a gigantic bump in grades that many people are happy to attribute to faculty helping them avoid the draft. Then, as they entered the faculty ranks, they continued the upward trend begun before the Vietnam era. There’s nothing new about modern grade inflation that wasn’t happening during the Baby Boom years, so the next time some older professor starts in on the “Back in my day…” routine, show him this graph, and tell him it’s all his fault.

(Of course, this model breaks down circa 1925, when a backwards extrapolation of the line would suggest that there were no A’s given out at all…)

Comments

  1. #1 Eric Lund
    July 19, 2011

    (Of course, this model breaks down circa 1925, when a backwards extrapolation of the line would suggest that there were no A’s given out at all…)

    Your model is actually fine. Note that the period 1940-1960 is compressed into the same space as any two years after 1960. What does change is the idea that baby boomers are solely to blame. The oldest baby boomers, apart from a handful of grade skippers, would not have hit college until 1964–they may have continued the trend, but they didn’t start it. You would have to blame their junior professors, who would have been born in the 1920s and early 1930s and therefore experienced the Depression as children. Or it could be related to the massive expansion of the availability of college education in the 1950s and 1960s (many colleges and universities, especially community colleges and non-flagship state universities, were founded during this period), which meant that people who didn’t fit the traditional crusty, hard nosed academic archetype (Prof. Kingsfield, to take a fictional example) were getting faculty positions.

    (P.S. You have forgotten to close the tag linking to Mike’s piece.)

  2. #2 Cosma Shalizi
    July 19, 2011

    There’s an unclosed anchor tag after “Mad Mike”.

  3. #3 andre3
    July 19, 2011

    Graph issues! Which grade is which?

    People who got red as a grade sure went up. People who got green sure went down.

    I take it red is A. Is green C?

  4. #4 mph
    July 19, 2011

    @3: The full legend is visible in the RSS feed, or if you view the image on its own (in Firefox, right click on the image, “View Image”). The blog formatting conceals the critical bit on the right. Red is A, Orange is B, Green is C, Blue is D, Purple is F.

  5. #5 Kate
    July 19, 2011

    I’ve been following this discussion on other blogs, and it seems to me that a lot of this boils down to this philosophy on the part of the older bloggers:

    “Our generation did better because we worked harder. This new generation does better because they have it easy.”

    and on the part of younger bloggers:

    “The older generation doesn’t understand the level of effort and commitment we have.”

    I’m not sure either hypotheses has been adequately supported.

  6. #6 Chad Orzel
    July 19, 2011

    Figure width and tag closure issues should be fixed now.

  7. #7 becca
    July 19, 2011

    I generally blame the babyboomers for everything (bad weather? blasted boomers) but your post does ziltch to explain the data. What is really going on here… what is different about the 1964-1974 AND 1988-2008 that did NOT apply from 1974-1988? It’s not like the babyboomers were all abducted by aliens during 1974-88. Although that itself would explain much…

  8. #8 CCPhysicist
    July 19, 2011

    As an interested observer at the time, I can tell you that grade inflation was produced by the “Greatest Generation” that made up the bulk of the faculty hired between 1960 and 1970. I’ll remind you of the PhD production in physics during the postwar period.
    http://doctorpion.blogspot.com/2007/07/physics-jobs-part-1.html

    These faculty, some of them WWII vets, were exceptionally against the draft for that “war” and changed their grade curves to keep those with student deferments in college. Flunk out of a university in 1967 and you went to Vietnam, not back to a CC. This is also why the population of Vietnam vets is so different from that in WW II.

    Those grade policies were obvious, although it wasn’t until I was a senior that I learned that the math department had an actual policy of giving an A to every student enrolled in a graduate course. (They easily made up for this in their lower undergrad classes.) As you can see, it tailed off a bit after that “war” ended, but I know for a fact that by that time it was only the math and natural science departments that gave out enough D or F grades to show up on that graph. It will come as no surprise to many that same fields identified as weak in Academically Adrift — Education, Business, Social Work — led the race to top GPAs.

    It should be no surprise that faculty hired in the 90s were a product of this system and continued to inflate grades in the social sciences. I see little evidence that public university grades in the natural sciences have changed much since 1974. We still fail students.

    However, there is also the factor of money. Notice the extreme inflation of private colleges? (Different graph than the one you showed.) Those aren’t all Harvard. The non-selective colleges need to retain their students to make their budget work. I have little doubt that the illusion that they are all above average helps justify those absurd grade distributions.

  9. #9 F-L
    July 19, 2011

    I think Kate’s comment is very on-target.

  10. #10 CaptainBooshi
    July 19, 2011

    becca, you do realize that from 1974-1988 on the graph is just the grade inflation returning to it’s steady increase after the huge jump that Vietnam gave it, right? That’s exactly what was different about that period. If you take the Vietnam bump out, you see that grade inflation was occurring at exactly the same rate as before and after.

  11. #11 ADD
    July 19, 2011

    What I find most remarkable is the drop in the percentage of Bs starting around 1990. The percentages of Cs, Ds, and Fs became so small that the number of Bs had to decrease to allow the number of As to rise. By contrast, in the Vietnam era the number of Bs rose.

  12. #12 Hamish Johnston
    July 20, 2011

    Before 1954 no-one could run a mile in under four minutes. Today, the four-minute mark is broken regularly. No grade inflation possible here, just the fact that modern training methods have improved runners.

    Couldn’t it simply be that students today are better trained and motivated than those in the past? It’s tough to admit if you are older, but I can’t see why it can’t be true?

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