Aaron Clauset, Sam Arbesman and Daniel Larremore have analysed some data comcerning career paths in computer science, business, and history. People won’t, I imagine, be that surprised at their findings…
First, academics’ career success largely depends on the prestige of the department where they did their PhD. Second, the system is so skewed in favor of academics who came from prestigious departments that it’s really hard to explain this by just saying that they are better than people who went to less prestigious departments. The evidence suggests “a specific and significant preference for hiring faculty with prestigious doctorates” even aside from differences in their productivity (which are also more skewed than one would expect if the differences were based on merit alone). The system is also significantly skewed against women in both computer science and business, although there’s no evidence that they’re discriminated against in history.
This – as others have pointed out – intersects with issues of class, since people from lower classes tend not to be at more prestigious departments. Whilst they didn’t examine philosophy, it seems very plausible the same story holds there too. Links to further info/data on this issue would be great.
You can read more here.