As school leaders, principals can influence student achievement in a number of ways, such as: hiring and firing teachers, monitoring instruction, and maintaining student discipline, among others. We measure the effect of individual principals on gains in student math and reading achievement...

This study extends recent findings of a relationship between the relative age of students among their peers and their probability of disability classification. Using three nationally representative surveys spanning 1988-2004 and grades K-10, we find that an additional month of relative age...