Would these people perhaps be clustered in a particular field? I'd guess that things are very different depending on the percentage of PhD's in a field who go into academia versus industry. For example, the academic job market for Astronomy is very different than CS, because there are many more non-academic options for CS graduates.

I think even an outstanding Astronomy PhD from a top tier university may find it difficult to get a tenure track position in their field. The same would probably be true for CS if all the graduates were to pursue academic positions, but since many go into industry, there is less competition for tenure track positions among those who want to teach.