Why do teachers quit?

New research on why successful teachers leave the classroom:

“As previous research has shown, it is not, contrary to popular opinion, students who drive teachers out of the classroom,” Dunn says.
But the negative factors—including lack of quality instruction time and low salaries—outweigh the positive aspects of teaching and lead teachers to quit... In addition, lack of support appear to play an important role. Teachers need more than professional development—they also need personal support, even if that’s a colleague or an organized group to talk to about the pressures they face, Dunn says.