The Wall Street Journal (5/14) recently reported numbers on the cost of low performing teachers on their students. Often protected by tenure laws that make it hard to remove poorly performing teachers, the difference between a teacher in the bottom five percent and an average one is $9000 in lifetime earnings lost for a student.

The Journal said ”The youth unemployment rate for those between ages 20 and 24 is 9.6%, compared with 4.5% for those 25 and over. But America’s double-cross doesn’t start when you receive your diploma. It has been going on since elementary school, with too many American children badly educated at schools where ill-qualified teachers are protected by unions.

As a result, the U.S. has steadily dropped in international education rankings—to an estimated 27th in mathematics in 2012 among Organization for Economic Cooperation and Development countries, down from 23rd in 2003. For those of you who majored in education, guess what? When bad teachers can’t be fired, there are fewer job openings for you.

Harvard economist Raj Chetty has estimated that replacing a teacher in the bottom 5% of skills with a teacher of average quality results in an extra $9,000 in lifetime income per student. Replacing the bottom 5% of the nation’s 3.3 million public-school teachers would have collectively increased the lifetime income of 2015 graduates by $31 billion”

Conservative reformers in the Legislature passed tenure reform but a union lawsuit blocked it. Reformers need to keep fighting to get rid of tenure and reward merit. It’s a shame to protect a bad system at the expense of children.