The Quality and Distribution of Teachers under the No Child Left Behind Act

T he heart of accountability under the No Child Left Behind (NCLB) Act is an attempt to change the existing incentives in schools with the ultimate objective that all students meet a profi ciency standard. Existing research indicates that nothing is more important to high achievement as having effective teachers, implying that the impact of new incentives on teachers will be central to any consideration of the accountability statutes. Tracing the impacts of NCLB on the stock and distribution of teachers is, nonetheless, a diffi cult and uncertain task. The belief that the quality of teachers matters a great deal to the quality of education received by students has actually proven hard to substantiate, and the reasons for this diffi culty are key to assessing the impacts of No Child Left Behind. A substantial body of research going back to the Coleman et al. (1966) report has attempted to link commonly used measures of teacher quality—such as experience, degree level, and state teacher certifi cation—to student outcomes. Surprisingly, except for perhaps the fi rst few years of classroom experience, no robust connection has appeared; for example, Hanushek and Rivkin (2006) review various studies attempting to identify characteristics of effective teachers. One The Quality and Distribution of Teachers under the No Child Left Behind Act