This year's battle over the introduction of Common Core standards in public schools has diverted attention from a more important but quieter battle led by teachers unions to eliminate school accountability and teacher evaluations. These two measures are the real engines that will drive educational improvement, and it's critical that attempts to do away with them be blocked.
The Common Core was designed to replace the hodge-podge of standards in place in the individual states with a national proclamation of what all students should know in each subject and grade. The standards were developed under the auspices of the National Governors Association and strongly backed by the U.S. Department of Education. Over the past five years, 44 states adopted them, although ordinary citizens and even many people in the schools didn't know much about them. The new standards also have led to a related movement to develop new tests of student performance planned for the 2015-16 school year. The Common Core standards were designed to move American students, who generally score below the developed-country average in math and science, up to world-class achievement.
A coalition generally consisting of conservatives called the Common Core into question, and some states have retreated from adopting them. One argument against the Common Core was that there was undue pressure on states to use them, in part because they were a requirement for states that wanted to get federal "race to the top" money. Education is the province of the states, critics say, and the federal government is prohibited from being involved in school curricula. Another argument is that the Common Core standards are in reality less rigorous than the standards in a number of states.
But this fight is not the real story. Declaring what students should know is far different than having them actually know it. Experience under the No Child Left Behind law (enacted in 2002) shows that many students have not reached proficiency even in states with weak standards. The performance of students across states is unrelated to the rigor of their existing standards.
Regardless of what or whose standards are adopted in the public schools, educational improvement requires strong accountability systems, rewarding teachers who are effective, eliminating teachers who are harming students, and providing added choice to parents about where their children go to school. Research has shown that these policies, while not silver bullets, each push toward higher student achievement.
While Indiana's withdrawal from the Common Core and Louisiana Gov. Bobby Jindal arguing with his state superintendent about withdrawing generate attention-grabbing headlines, the teachers unions are working behind the scenes across the nation to gut teacher evaluations and to "suspend" school test accountability under No Child Left Behind so that teachers can prepare for the new tests—however long that might take.
Even true reformers like Kaya Henderson, superintendent of the Washington, D.C., public schools, have implicitly aided this union effort. Two weeks ago, Ms. Henderson announced that the use of student-achievement measures in assessing teacher performance was being suspended because of delays in getting new test data.
This is unfortunate. Washington, D.C., has been the prototype of school reform since it introduced a visionary teacher-evaluation system in the 2009-10 school year. This system, called IMPACT, combined information on student achievement with rigorous observations of teachers to produce a rating of individual teachers. (Because of special congressional authority, IMPACT did not have to be negotiated with the union.) Teachers rated highly effective for two years received bonuses and even increases in base salary. Teachers rated minimally effective for two years were dismissed. During the first three years of operations, about 1,000 teachers were rewarded for top performance, while around 350 were dismissed.
A convincing evaluation of the IMPACT system published by the National Bureau of Economic Research by Thomas Dee of Stanford and James Wyckoff of the University of Virginia showed that the incentives in this contract were producing very positive results—getting teachers on the borderline of dismissal or of reward to elicit higher student performance and inducing a number at the bottom to voluntarily leave. Moreover, according to the most recent data from the National Assessment of Educational Progress (the "Nation's Report Card"), student achievement in District of Columbia Public Schools improved more than achievement in any other of the 21 participating urban districts between 2011 and 2013. It was the only one of these large districts, including New York City, Los Angeles, Chicago, Dallas and Houston, where students moved forward in all tested subjects—reading and math in grades 4 and 8—and in each case the absolute gains in D.C. were larger than the next-best district.
The Common Core debate has given the teachers unions the opportunity to argue that it would simply be unfair to judge teachers on student performance in the face of new standards and new tests. Resisting accountability is not a new position of the unions, but the Common Core standards give them a new hook.
Rigorous standards for what we expect from students are undoubtedly valuable. At the same time, we cannot afford to back away from policies that actually have been shown to have a clear impact on student achievement.
Mr. Hanushek is a senior fellow at the Hoover Institution of Stanford University. He is co-author of "Endangering Prosperity: A Global View of the American School" (Brookings, 2013).