Henry Levin and Cecilia Rouse:

ONLY 21 states require students to attend high school until they graduate or turn 18. The proposal President Obama announced on Tuesday night in his State of the Union address — to make such attendance compulsory in every state — is a step in the right direction, but it would not go far enough to reduce a dropout rate that imposes a heavy cost on the entire economy, not just on those who fail to obtain a diploma.
In 1970, the United States had the world’s highest rate of high school and college graduation. Today, according to the Organization for Economic Cooperation and Development, we’ve slipped to No. 21 in high school completion and No. 15 in college completion, as other countries surpassed us in the quality of their primary and secondary education.