Compared to other developed countries, the US ranks high on income inequality and low on social mobility. This could be particularly concerning if such a trend is self-perpetuating. In this column, the authors argue that there is a causal relationship between income inequality and high school dropout rates among disadvantaged youth. In particular, moving from a low-inequality to a high-inequality state increases the likelihood that a male student from a low socioeconomic status drops out of high school by 4.1 percentage points. The lack of opportunity for disadvantaged students, therefore, may be self-perpetuating.