Even then, 1 year off is a 20% income reduction on paper. 2 years would be 40%. Want to catch people voluntarily taking off work versus being 'legitimately' unemployed? (For example, is a realtor with no income during the housing crisis adequately poor?) Then, every university will have to hire people to do the analyses and make value judgements.

Long term, factoring in wealth creates all sorts of perverse incentives for parents that prioritize their children's education. It means in the present not taking promotions, even negotiating for lower salaries, and being priced out of better neighborhoods with better schools, all out of fear that doing otherwise will hurt their children's futures. And if their children succeed in getting a good education and a high-paying job, it comes at the cost of sacrificing their own children's futures.