These ROI calculations on degrees are more of a (flawed) basis for encouraging (less often, discouraging) college. They are not useful. It may seem like a good idea to develop an "ROI for college", but it distracts from what's important. First, much of the value of a degree is in getting your first job (networking at elite schools must be helpful however). As your career progresses, the importance of having a degree…
If you want to be a splashy top executive, it's very helpful to have a top-tier MBA, and experience in management consulting or investment banking. If you want experience in IB or MC, it's very helpful to have an ivy league undergrad degree, ideally in something like econ.
If you want to be a great engineer, it's very helpful to go someplace, hang out with smart people, take hard classes, write code outside class, and make sure you make the most of the experience, wherever you are.
If you want random assholes to think that you're a great engineer, it's very helpful to go to MIT, Stanford, or CMU, and just make sure you don't do so poorly that you don't graduate.