Making sure we identify poor teachers and have them exit the teaching profession should be of the utmost importance. This is because teachers, by far, have the single biggest impact on student success.

As teachers’ strikes continue to spread across Illinois, union officials are pushing back against criticisms that they are not doing enough to raise student achievement. One of the most common excuses they use to explain the lack of results – apart from claiming that low-income populations have too many issues to overcome, something the Institute showed is...