Association for Public Policy Analysis & Management

The Common Core State Standards were an ambitious effort to raise expectations for students, utilize next generation assessments, and hold schools accountable for results. State education leaders, foundations, and the federal government all provided funding and political support for the Common Core. But, the research on the effect of the standards is mixed. States that strongly invested in Common Core implementation had state average 4^th grade reading NAEP scores that were somewhat higher (0.03 to 0.04 SDs) than states that did not adopt the Common Core (Loveless, 2015). An updated analysis (Loveless, 2016), found that states that had implemented Common Core to varying degrees had similar outcomes. Rigorous standards (like the Common Core) had insignificant effects up to 5 years after implementation (C-SAIL, 2018).

The power of these studies to detect significant results and heterogeneous effects is limited by using average state test scores as the outcome. I ask: To what extent does implementing Common reform affect student achievement? Does implementation of Common Core exacerbate achievement gaps between white and black students?

To answer this question, I utilize the student-level data from the main National Assessment of Educational Progress (NAEP). My preliminary analyses pools together 4 subject/grade datasets (4th grade math, 8th grade math, 4th grade reading, 8th grade reading). In each the outcome is standardized by subject/grade and year. The final dataset uses six waves of NAEP data (odd years from 2003-2013). I merge into these data my independent variable, a binary indicator for whether a state reports full implementation of the Common Core in each of the 4 subject/grade datasets. I created this measure using survey data from state education officials about their implementation of the standards (Achieve, 2013). This analysis estimates the effect of Common Core implementation in 2013 compared to achievement in prior years. This approach avoids confounding the effect of the Common Core Assessments, which were first implemented in 2015.

I estimate the causal effect of Common Core on student outcomes using a difference-in-differences (DiD) model with district fixed effects. This approach requires that district implementation of Common Core is exogenous—if the same dynamics that led states to adopt the Common Core also directly affected student achievement then the estimate will be biased.

Preliminary DiD results suggest Common Core has a positive and significant effect on student achievement. The effect of Common Core in the pooled model with district fixed effects is relatively small (0.04 SDs). Common Core appears to primarily benefit white students. It’s implementation significantly increases achievement gaps between white and black students (0.07 SDs). When the effect of Common Core is estimated by subject/grade the effect remains positive but is only significant in 8^th grade math.

In addition, I plan to collect additional information on the rigor of the standards used prior to Common Core to estimate a comparative interrupted time series that controls for pre-treatment trends. In addition, I hope to append the 2015 NAEP data.