Massachusetts high school students would be required to stay in school until age 18 under a bill approved Thursday by a legislative panel hoping to reduce the number of students who drop out of school, the Associated Press reports. The compulsory school attendance age in Massachusetts is currently 16, with certain exceptions for children as young as 14. In addition to raising the dropout age to 18, with no exemptions, the bill advanced by the joint Education Committee contains other proposals to get students “across the finish line to graduation,” said Sen. Sonia Chang-Diaz, D-Boston, who co-chairs the panel. President Barack Obama, in his State of the Union address in January, called on every state to require students to stay in high school until age 18. Twenty-one states have an 18-year-old dropout age, including Rhode Island, where Gov. Lincoln Chafee signed legislation last summer raising the mandatory attendance age from 16…