Eric Hanushek, a Stanford economist, emphasizes the significant impact of teacher quality on student learning outcomes. He estimates that students taught by ineffective teachers learn only about half a year’s worth of material in a single school year, while those with highly effective teachers can learn a year and a half's worth. This striking contrast indicates that having a great teacher can lead to a substantial increase in student achievement, effectively making up for deficiencies in school quality.

Hanushek's findings suggest that the influence of a teacher far outweighs the advantages of school reputation or resources. A child learning in a poor school but under the guidance of an exceptional teacher has better prospects for learning than a child in a well-funded school taught by an inadequate teacher. This perspective challenges the notion that school environment alone determines educational success, highlighting the crucial role of effective teaching in shaping students' futures.