“Zero tolerance” disciplinary policies arose in the late 1980s and early 1990s in response to perceptions of rising school violence. The concept was simple: Students who committed certain infractions were to be expelled or given out-of-school suspension regardless of individual circumstances.

As income inequality has continued to rise in the United States, scholars have been examining the deep structural issues that may help drive this trend. Some research has documented how certain public policy choices — or decisions not to address pressing problems in a changing economy — has been at the heart of this issue.