Oh good. Otherwise, I was going to have to have a chat with Sahana about her tuition at CMU. :-)
This graph does not in any way prove that investing in education yields negative returns. It shows that a yearly wage is cheaper than the cost of a four-year degree. That stinks, but, you know, workers don’t retire at 23. They retire closer to 63 or 73. In those 40 or 50 years, college is an appreciating asset. Like a ladder to an escalator, it both gives you access to higher pay out of college and puts you on a path to rising wages that high-school-only grads are locked out of. You won’t find that in the graph.