In an article in the Atlantic, Joel Klein, the former chancellor of New York City, suggests implementing a teacher bar exam to improve teacher quality. 

Contrast that with America, where virtually anyone who graduates from college can become a teacher, and where job security, not teacher excellence, defines the workforce culture. According to the consulting firm McKinsey, "The U.S. attracts most of its teachers from the bottom two-thirds of college classes, with nearly half coming from the bottom third." And, today, more than a third of math teachers in the U.S. don't have an undergraduate degree in math, let alone a Master's degree. Yet, even with this remarkably low threshold for entry, once someone becomes a teacher in the U.S., it's virtually impossible to remove him or her for poor performance.

He proposes a rigorous examination that would force education schools to increase their standards and then a multi-year internship. 

What do you think?