Evidence That Smaller Schools Do Not Improve Student Achievement

If more small schools than "expected" are among the high achievers, then creating more small schools would raise achievement across the board, many proponents of small schools have argued. Mr. Wainer and Mr. Zwerling challenge the faulty logic of such inferences. ********** It was the best of times, it was the worst of times, it was the age of wisdom, it was the age of foolishness, it was the epoch of belief, it was the epoch of incredulity. -- Charles Dickens, A Tale of Two Cities THE urbanization that characterized the 20th century led to the abandonment of the rural lifestyle and, with it, an increase in the size of schools. The time of one-room schoolhouses ended and was replaced by the era of large schools, often with more than a thousand students, dozens of teachers of many specialties, and facilities that would not have been practical without the enormous increase in scale. Yet during the last quarter of the 20th century there were rumblings of dissatisfaction with large schools, and the suggestion that smaller schools could provide better-quality education gained adherents. (1) In the late 1990s the Bill & Melinda Gates Foundation began supporting small schools on a broad-ranging, intensive, national basis. By 2001, the foundation had given approximately $1.7 billion in grants to education projects. It has since been joined in support for smaller schools by the Annenberg Foundation, the Carnegie Corporation, the Center for Collaborative Education, the Center for School Change, Harvard's Change Leadership Group, the Open Society Institute, the Pew Charitable Trusts, and the U.S. Department of Education's Smaller Learning Communities Program. The availability of such large amounts of money to implement a smaller-schools policy yielded a concomitant increase in the pressure to do so, with programs to splinter large schools into smaller ones being proposed and implemented broadly in such cities as New York, Los Angeles, Chicago, and Seattle. What is the evidence in support of such a change? Many claims have been made about the advantages of smaller schools, but we will focus here on just one--that when schools are smaller, students' achievement improves, all else being equal, of course. The supporting evidence for this contention is that, when one looks at high-performing schools, one is apt to see an unrepresentatively large proportion of smaller schools. But seeing a greater than anticipated number of small schools in this group does not imply that being small means having a greater likelihood of being high performing. KIDNEY CANCER To illustrate our point, consider the example of kidney cancer. Figure 1 is a map of age-adjusted kidney cancer rates for men. The shaded areas are those counties that are in the lowest decile of the cancer distribution. We note that these healthy counties tend to be rural and located in the Midwest, the South, and the West. It is both easy and tempting to infer that their low cancer rates are directly due to the clean living of the rural lifestyle--no air pollution, no water pollution, and access to fresh food without additives. [FIGURE 1 OMITTED] Figure 2 is another map of age-adjusted kidney cancer rates. Though it looks much like Figure 1, it differs in one important detail--the shaded counties are those in the highest decile of the cancer distribution. Note that these ailing counties tend to be rural and located in the Midwest, the South, and the West. It is easy to infer that their high cancer rates might be directly due to the poverty of the rural lifestyle--limited access to good medical care, a high-fat diet, too much alcohol, and too much tobacco. If we were to plot Figure 1 on top of Figure 2, we would see that many of the shaded counties on one map are right next to the shaded counties on the other. So what is going on? What we are seeing is variance. The variance of the mean is proportional to the sample size; thus small counties have much larger variation than large counties. …