The introduction of student accountability systems across the United States has been controversial both because of its focus on standardized achievement tests and because of questions about its effectiveness. Past evidence, however, shows that performance on standardized tests of the type central to state accountability systems has powerful economic effects. Additionally, analysis of performance across states indicates that accountability policies in general lead to higher levels of achievement, though the magnitudes of the effects are influenced by the design of the policy. Finally, however, despite positive effects overall, recent work shows that these policy instruments are not effective at closing the black-white achievement gap.