I'm actually not convinced that making it a higher percentage threshold doesn't make cooperation less likely at 10% (depending on class size) each student real

I'm actually not convinced that making it a higher percentage threshold doesn't make cooperation less likely at 10% (depending on class size) each student realizes that their noncooperation goes a good distance of the way towards that 10% at say 50% threshold, each student thinks their noncooperation matters less, and thus is even less likely to cooperate at least that's what I'd hypothesize, I suspect there is an interesting paper somewhere that explores this very phenomenon