Schools are remarkably insular institutions, so "Have I improved?" is an especially difficult question for principals. Sure, schools are filled with people. Despite the schoolwide assemblies, faculty meetings, and crowded halls, much of what principals do is unseen and unknown by other adults. A big portion of principals' time is spent…

The authors provide an updated analysis of demographic trends in teaching profession, finding that the profession is growing, becoming more inexperienced, and more diverse. The trends and others, they write, shed light on the teacher pipeline today and offer insights on teacher-staffing issues, even as they raise important policy questions.