There is widespread concern that elementary and secondary school education in the United States is deteriorating and is now inferior to that of many other countries, as measured for example by high-school graduation rates and college attendance rates. Proposals for reform fall into two main classes: increasing competition in the provision of educational services; improving the quality of public school teachers.
A reform aimed at improving the quality of public school teachers that has received a good deal of attention lately is the “value added” method of evaluating teachers’ performance, now being used in the public schools of Los Angeles. See “Grading the Teachers: Value-Added Analysis,” www.latimes.com/news/local/teachers-investigation/. The evaluation begins with determining the average improvement of a student, say between the end of third grade and the end of fourth grade, and then comparing the student’s actual improvement, all as measured by performance on standardized tests. If his or her improvement is above the average improvements, the teacher is rewarded, for example with a bonus; if below, the teacher can be counseled in an effort to improve the teacher’s performance. The Secretary of Education, Arne Duncan, supports value-added teacher evaluations (and informing parents of the teachers’ scores); the teachers’ unions oppose it as a step toward merit-based pay of public school teachers or even elimination of tenure.
The main objection to the program is that the value added by a teacher can’t really be measured. The reason is that much may influence a student’s performance (including his year-to-year improvement) besides the teacher, including fellow students, conditions at home, and the student’s intelligence and application. These other factors could in principle be controlled for, but actually to do so would probably strain the ability of public school bureaucracies to devise and administer sophisticated statistical measurements. The alternative would be to assume that differences across students average out. But unless classes are very large and students are assigned to teachers randomly, differences in average performance are unlikely to be statistically robust.
The value-added methodology is, moreover, very difficult to apply beyond elementary school. When students have more than one teacher at a time their progression from year to year is the result of a team effort, and it is difficult to identify the contribution of each teacher. Even if improvement (or lack thereof) is measured on a subject-by-subject basis, the existence of complementarities between subjects (math and science, for example, or history and social studies) means that a teacher in one subject can influence student performance in another. And the complementaries can be subtle: an excellent English teacher may inspire her students with enthusiasm for school in general, stimulating them to improve their academic performance in unrelated courses.
Even with all these difficulties acknowledged, the granting of bonuses to teachers who receive above-average value-added evaluations would have some good effect on teachers’ motivation. But of course the money has to come from somewhere, and the benefit may not equal the cost. It is doubtful, moreover, that value-added evaluations, even when publicized (as the Los Angeles Times did recently with the L.A. public schoolteacher evaluations, causing a good deal of commotion and, it seems, the suicide of one teacher), have much effect on bad teachers, either by causing them to improve or by easing them out of the system. The methodology is too crude (and likely to remain so) to provide a solid basis for censure, self-criticism, instituting a system of merit pay, or ending teacher tenure. Tenure has of course bad effects, whether it’s tenure in public or private schools, in public or private universities, in the federal judiciary, or unionized workplaces: it encourages slacking off, selects for people who have a high degree of leisure preference, and leads to retention of poor performers. At the same time, however, it is a form of compensation valued by many; were it eliminated in public schools, the schools would have to pay higher, maybe much higher, salaries, which hardly seems feasible in today’s economic climate (which is likely to be tomorrow’s too).
So value-added evaluation of public schoolteachers, while ingenious (despite its limitations) and growing in popularity, does not seem to be the answer, or even a major part of the answer, to dissatisfaction with American education. Competition is more promising. Two forms should be distinguished: charter schools, which are public schools (that is, publicly financed and tuition free) that are however managed outside the normal public school system in order to enable and encourage experimentation; and means-tested vouchers, which are scholarships that a student can use to attend a private (including parochial) school. About a million students are enrolled in charter schools, and 200,000 other students receive vouchers enabling them to attend private schools. Home schooling is another alternative to public schools, and an important form of competitive education, but it is not feasible for students from poor homes because their parents (often just a mother) rarely have enough education for them to able to teach their children.
The charter schools have turned out to be a mixed bag. There is excess demand for them, which is some evidence that they are superior to public schools. But studies of drop-out rates and other measures of quality indicate that while some charter schools are indeed better than public schools, many are worse; there is as yet no convincing evidence that on balance they are superior to public schools. There is more evidence that vouchers improve educational performance, though it is not conclusive. See “Is School Choice Enough?” www.city-journal.org/2008/forum0124.html. Vouchers enable poor students to attend established schools with a proven record of quality (many of these are Catholic parochial schools), so it is not surprising that they are more effective in improving academic performance than conversion of existing public schools to quasi-private status, which is the character of the charter-school movement.
Teachers’ unions are more fiercely opposed to vouchers than to charter schools, which is a vote in favor of vouchers! Private schools have greater freedom from regulation and are less likely to be unionized than charter schools (although charter schools, too, are generally not required to bargain collectively with their teachers), and they are numerous and established and can expand to accommodate increased demand.
I favor vouchers, but they are no panacea. Obviously, basic education is an important social good. But even bad schools provide that. How much value good schools can add to the skills and knowledge of students who now attend bad schools is uncertain. Maybe most students who attend bad schools have limited aptitude and motivation because of low IQ, poor physical or mental health, peer-group pressures, a bad family environment, or effects of popular culture. How far such impediments to academic performance can be remedied by teachers, however skilled, and at what cost, is unclear to me.