This question is an off-shoot from this one, where it has been agreed by most that securing faculty positions is difficult in general. I would like to know what exactly makes this so.
Though in theory university rankings may be pointless, there is a broad quality-based classification of institutions in any country which many will agree on - for example, the crème de la crème, top tier, middle tier and decent universities, of which there could be a few hundreds. We shall assume the student has passed out with a good thesis and impactful publications.
- Is it tough for a student graduating from a higher rung to gain a position in the lower rungs?
- What factors dictate the difficulty in securing a position in a university in the same league?
PS: In India, the answer to Q 1 is "not at all", as there is a heavy crunch for faculty positions even in top institutes. Instead the difficulty arises only when students from low rung colleges seek top positions: in most cases, such students are found wanting in skills.
It is difficult because there are more graduating PhDs than there are faculty positions. This is because by and large, academic departments are not growing very fast.
Consider a department that has 40 faculty positions, and is not growing. Suppose each faculty member has a career that spans 40 years (Say, ages 28-68). Then in a steady state, this department will hire 1 new faculty member every year. On the other hand, say each faculty member graduates 1 student on average every three years. (This is conservative: say each professor has only 2 students at a time, and each one takes 6 years). So this department graduates 13-14 students every year.
This is what happens in general: each department produces many more PhDs than it consumes, so there must be many who leave the system.