Part three

The students just below the top benefited the most

North Carolina used a four-level scale then, and Level 4 was the highest. The research followed students at the top level and at the level immediately below it. The striking result is that the second group gained more, not less.

Students at the top scoring level who took 8th grade Algebra were three times as likely to take chemistry and physics as equally high-scoring students who waited. Students at the second-highest level were 55 times as likely. On the SAT, top-quartile students who took 8th grade Algebra averaged 634 in math against 599 for their equally capable peers who waited; in the next quartile down it was 562 against 537. Every comparison is between students with the same scores. The only difference is when they were allowed to start.

Hold onto that 55. A law that draws its line at the single highest score is drawing it above the students the evidence says gain the most.