Nothing Defines America’s Social Divide Like a College Education – Atlantic
Nothing except income, which is heavily correlated with education.
Share of education expenditures in household income by income – China

“In China, families in the highest income quartile allocate 10.6% of their income to children’s education. However, what is even more striking is that families in the lowest income quartile spend a significantly larger proportion of their income (56.8%) on education, leaving very little for other expenditures (Figure 5). Most of these burdensome expenses are not attributed to private tutoring but rather to in-school costs, which is ironic considering that the majority of schools in China are publicly funded and provided.”