On paper there can't be a U.S. pub- lic-schoolteacher shortage. Each year the nation's colleges turn out 200,000 graduates qualified for teaching, and 150,000 take jobs. That is 50,000 more than the net loss from teachers who retire or quit. Since the school population is growing at about 1,000,000 a year, these graduates should provide one new teacher for every 20 children—an admirable ratio. Yet as schools opened this month, the teacher shortage was the worst since World War II.
Caught aback, the National Education Association made an emergency survey, pegged the nationwide...