In the United States and in many other nations worldwide, there is now a consensus that teacher quality is among the most important factors, if not the essential factor, in the overall success of schooling and the educational system, which in turn determines a nation's ability to compete in the global knowledge economy. Accordingly, over the past decade, the recruitment, preparation, and retention of teachers has become a central concern of leaders in the business, philanthropic, and policy-making communities as well as in the professional arena. Along these lines, there has been a steady stream of position papers, think tank reports, and new policies or policy proposals regarding teacher preparation along with a great deal of controversy.

Like policy regarding other public services in the ...