This dissertation seeks to answer the question: Does pressuring teachers to raise their expectations increase student achievement? Drawing from the sociology of education, educational psychology, and the research on accountability systems, the author constructs a more comprehensive model of the association between teacher expectations, accountability interventions, and student achievement than has been offered in prior research. The author argues that prior research on accountability interventions focuses on the direct relationship between accountability testing and student achievement, but ignores how teachers mediate this association. To this end, prior research ignores the important role that teachers may play in communicating expectations shaped by accountability policies. Using data drawn from the Education Longitudinal Study matched to a unique state-level accountability dataset, this dissertation offers a systematic assessment of how public school teachers respond to accountability interventions with regard to their expectations for students. Findings show that teacher expectations are important predictors of student achievement, which is consistent with prior research. What prior scholars and policymakers have failed to appreciate, however, is that pressuring teachers to raise their expectations has unanticipated and counterproductive consequences on the very students the policies are intended to help. Rather than raising their expectations of students, teachers appear to use the information gathered from tests to lower their expectations or even to justify their already low expectations of students, especially for low-performing students. In spite of their lower expectations, the association between teacher expectations and student achievement is stronger in these states because teachers adjust their expectations of students. Further analysis shows that a student's race is an important determinant of teacher expectations. Teachers hold black and Hispanic students to lower standards than their white and Asian peers, and these low expectations contribute to the achievement gaps between white, black, and Hispanic students.