Many adults have vivid recollections of one or more teachers who had a profound impact on their lives. In contrast, few can even recall the name of their school principals. Research indicates that principals are second only to teachers as the most important school factor affecting student achievement—yet their contributions are often underappreciated. As school leaders, principals influence student achievement in many ways: establishing a vision that motivates the entire community, building a school culture that supports student learning, ensuring resources are used effectively, and engaging with the community. Most importantly, though, principals influence the quality of instruction in every classroom, by hiring, monitoring, evaluating, and supporting teachers. A good principal hires the most effective new teachers, establishes high expectations for all teachers, and provides them with feedback and support so they can continue to improve. In this way, one good principal can affect dozens of teachers and hundreds—even thousands—of students.
In recent years, districts and states have been focusing a lot of time and money on efforts to improve teacher quality, and rightly so. But it is impossible to have consistently high-quality teaching without a good principal in every school. Effective teachers don't want to work for ineffective principals, and many teachers report that they would leave their school or the teaching profession entirely rather than continue to work for an ineffective principal.
But districts face serious challenges finding and keeping good principals. Turnover rates are substantially higher in some districts than in others, and worse in high schools than in elementary schools. Furthermore, the turnover problem tends to be more serious for low-performing schools. Roughly one in three new principals in 10 urban districts we studied left their schools within three years.
This revolving door in the principal's office is disruptive for the school community, especially for teachers. Research shows that schools that lose a principal tend to underperform in the next year, and it can take up to five years to get back on track. High principal turnover imposes financial costs on districts as well. A study by the School Leaders Network estimates the cost of replacing just one principal at about $75,000.
So what does it take to retain a new principal? Two key enabling conditions are having a strong pool of candidates and supporting them to be effective leaders. Districts can improve the quality of the candidate pool by working with institutional programs that target aspiring principals or by cultivating educators in the district who have strong leadership potential. A deeper candidate pool provides districts with an opportunity to match candidate strengths with the needs of the school. Once a new principal is on board, districts can improve the chances of success by providing resources such as mentoring, coaching, and principal support networks. Our study of the New Leaders' principal preparation program showed rigorous recruitment, high-quality training that balances theoretical and practical instruction, ongoing mentorship, and support from districts had a positive impact on retention rates and on student achievement outcomes.
It is understandable that for many, investment in preparing and supporting principals is a tough sell. After years of austere budgets, states and districts are pushed to spend money on things that influence the classroom directly, such as technology, study materials or lower student-teacher ratios.
But failing to invest in school leadership has costs as well. Professional development for aspiring and current principals is not simply a nice—if unessential—perk. As principals spend more time at a school and become more effective, they are able to transform their teaching staff. With the ripple effect this can have on students, the question may not be can we afford to invest in principals, but can we afford not to.
Susan M. Gates is a senior economist and director of the Office of Research Quality Assurance at the nonprofit, nonpartisan RAND Corporation.
