There's also "degree inflation" to take into account. There are so many people in the labor force with university degrees that it stops being a differentiator i

There's also "degree inflation" to take into account. There are so many people in the labor force with university degrees that it stops being a differentiator in the marketplace so job descriptions update to a new differentiator and start requiring post-grad degrees. Soon after entire school districts require a Masters degree to even start the interview process. Then that becomes enough of a norm that Universities pick up on that and make it a part of their positioning/marketing/"good advice" to students: you need at least a Masters if you want a job, so you should plan for a Masters. Targeted schools start to appear such as 5-year Masters programs designed to build so much inertia (taking Masters courses alongside junior/senior undergrad courses) and indeed sunk cost that the Masters seems like the natural outcome rather than the optional "next step". (Disclaimer: my own graduate degree was probably an expensive mistake that sometimes I regret and sometimes I'm quite proud of even if the job market doesn't care. My experience is not entirely related to the Masters of Education snowball described above, but I can see that snowball having happened from the outside a bit easier knowing what my own experience was.)