You'll notice a lot of people commenting here "my wife is a teacher" (myself included). I think these statistics are missing two very big factors.

- In high cost areas like the Silicon Valley, almost every teacher is married to an engineer or is the child of an engineer. That is why they don't need a second job. Because they have a support network.

- Teacher quits are low because most of the people who would be great teachers simply never get into the job because of the crappy pay and work conditions. The people who are the best at it could easily get other jobs. My wife if a great example -- during the summer she worked a temp job in the first few years that was basically a management job that would have an annual salary in the six figure range. She only kept doing teaching because she loved it and because I made enough money to support us.