Some teachers, under a professional cloud, are paid to leave their jobs. It is a fact little examined in schools or policy circles, and mostly unknown to the public. But when it does surface, it inevitably raises fears that teachers who should be out of the classroom entirely are helped to new teaching jobs at public expense. Defenders of the practice--administrators, union officials, and their lawyers--do so with a nod to an imperfect world. Most say that legal and social changes related to teacher misconduct have made it harder in recent years for teachers to hide illegal or immoral behavior and get new jobs. "Buyout" options, many of those involved say, are mostly reserved for teachers who are under suspicion of inadequate performance in the classroom or unprofessional conduct, such as yelling at parents or supervisors. In other instances, safeguards for schools are built in to the settlements, such as teachers' surrendering their licenses. Without the agreements, proponents say, districts would use far too many resources--in money, time, and morale--shedding tenured teachers they don't want. And such teachers who are ready to leave the profession for good or who need a new setting to prove their mettle can make those moves with less wear and tear, the defenders explain.