The Unintended Consequences of School Curricula Reforms : Examining Spillover Effects of Us Education Standards

School curricula have lasting impacts on students. In theory, reforming school curricula can be a powerful tool for policy-makers, but may also be harmful. To empirically prove the latter, we analyse the adoption of the Common Core State Standards (CCSS) for math and English in the US. We estimate spillovers of the CCSS on student achievement in non-targeted subjects such as science and social studies in models with state and year fixed effects. Using individual-level student achievement data from NAEP, we show that the CCSS had a negative effect on student achievement in non-targeted subjects. This effect is largest for young underprivileged students. To uncover mechanisms, we use teacher surveys to show that the CCSS reduced the instructional focus on non-targeted subjects. Our results call for a careful evaluation of potential spillovers on non-targeted outcomes when designing targeted education reforms