Your "period" makes me think about more questions, not less.

1) Will that still hold in 2070? Kids who are now 18 are likely to be working at least until then. How do the developments over time look like? Won't the increasing shortage of tradespeople drive up their compensation?

2) How does a finer division by majors look like? I would be surprised if every major out there made more money than, say, an electrician.

3) Lifetime is a very long timespan. College grads are deeply in their debt in their 20s and 30s, so they can afford starting a family less. They will be better off when they are 50, but in the meantime they possibly sacrificed a an unborn kid or two to their tuition debt. This is a nasty tradeoff.