High standards for schools will not benefit California if the state lacks enough good teachers. Recent state efforts have cut the number of underqualified teachers in California classrooms. But the governor and Legislature still need to address the huge challenge of ensuring a sufficient supply of first-rate teachers.

A report by the Center for the Future of Teaching and Learning, released last week, says only about 18,000 California teachers lacked a proper teaching credential or taught outside their area of expertise in 2005-06. That number is far better than the more than 42,000 underprepared teachers the state had in 2000-01.

And legislators this year passed bills that streamlined the process of becoming a teacher, boosted teacher improvement programs and targeted more money toward the poorest-performing schools.

Despite those efforts, California struggles in many ways to supply classrooms with good teachers:

The lowest-performing schools still have the highest proportion of inexperienced teachers. So the schools that need the best teachers end up with the least-qualified. California could change that dynamic by offering bonuses, higher pay and more teacher training to lure top teachers to poorer schools.

California lacks enough qualified special education teachers, especially in the poorest schools. Likewise, California faces a shortage of qualified math and science teachers. The state needs to give incentives and training to encourage more teachers to concentrate on these vital specialties, and to boost the skills of those already in the classrooms.

As many as 100,000 teachers will retire over the next decade. Yet the number of people studying to become teachers in California is declining. California should provide grants, tuition aid and other support to encourage students to enter teaching, and make sure public colleges have the capacity to turn out enough new teachers.

California created a host of teacher recruitment and training programs in the late 1990s, only to abandon many of these incentives during the budget crises of the early 2000s. But building a supply of strong teachers requires constant attention, not policy that ebbs and flows with political tides.