Schwitzgebel's study of CP names in top mainstream journals

Eric Schwitzgebel has a very interesting quantitative study on citations of CP figures in three top mainstream journals (Philosophical Review, Mind, and Journal of Philosophy) from 1900 to the present. Confirming the impression most people have (and that we informally surveyed here), the study shows that CP citations have declined relative to the whole as time goes on.

The trends started rapidly pulling apart in the 1950s through 1970s and have continued to slowly pull farther apart since then.

His conclusion for recent years:

In the 1990s and the portion of the 2000s that has so far been indexed in JStor, the words Nietzsche, Heidegger, Sartre, Foucault, and Derrida appeared in 45 articles total among 1209 Big Three journal articles (3.7%). Thus, the Big Three journals have included, on average, about one article per journal per year that even passingly mentions any of these five authors.

Some thoughts below the fold:

Follow up studies might look to see: 

1. in-depth discussion vs mere mention (e.g., a note saying, "see also Heidegger, Being and Time.")

2. respectful discussion ("although I strongly disagree with his conclusion, Heidegger's analysis of authenticity in Being and Time is important even in its errors") vs sneering rebuke ("although it pains me to do so, we should spend a little time showing just how wrong-headed Heidegger is in his discussion of authenticity...")

3. the respect vs sneer ratio for each CP figure (i.e., does Foucault get more respect than Derrida, for instance) -- also, does this ratio change over time? 

4. is the respect vs sneer ratio different for German vs French figures? 

5. what internal and external factors can account for the divergence period of the 1950s to 1970s?

6. what factors keep that divergence going?