Is Common Core The Answer to Flat SAT Scores?

StateEducationTrendAndrew Coulson has published a new paper on State Education Trends. Here is a quote and graph from the paper. I guess this is not surprising but it begs the question whether common core is the answer.

The performance of 17-year olds has been essentially stagnant across all subjects despite a near tripling of the inflation adjusted cost of putting a child through the K-12 system.