Comment by Clubber

>Now they're a year behind academically

I think you're missing something. Getting expelled doesn't mean you didn't attend school for the remainder of the year. Getting expelled meant you were sent to a school for expelled kids. If you got expelled from there, you went to a school for expelled x2 kids. In the US, it's illegal to not attend school under the age of 16.

>and have the shame of being expelled.

Shame is a powerful motivator, but only works sometimes. The alternative is to ignore the behavior or reward it, both worse solutions IMO.

I think the idea is if kids are disruptive, put them with other disruptive kids so the amount of disruption is minimized. All the kids in the disruption school are already disruptive. Also, you don't want to teach the current non-disruptive kids that being disruptive is acceptable, otherwise, you'll just create more disruptive kids by inaction.