Randi Weingarten, president of the American Federation of Teachers (AFT), proposed a "bar exam" for public-school teachers in a Wall Street Journal op-ed last week. Modeled after the bar exam for aspiring lawyers, the new test would be intended to produce highly effective teachers. But it would do nothing of the kind.
As we have explained before, passing a certification test has no impact on a teacher’s effectiveness. These tests are just barriers to entry that would discourage high-quality people from entering the profession in the first place. Existing teachers stand to benefit from these barriers, since they would limit competition and potentially push up wages, but students and taxpayers would certainly not benefit.