America is a mobile society. In fact that has been one of its strengths; the American labor market adjusts to changes more quickly than virtually any other labor market in the world. But mobility has its costs. Family moves, whether for new job opportunities, improved housing, or adjustment to divorce, lead to frequent changes of schools. These school changes take their toll on some children.
Moreover, the negative effects of moving are not only experienced by the children who move; all students in high-mobility schools, including nonmovers, tend to be affected. Teachers must continually adjust to movements in and out of their classrooms, and these adjustments detract from learning.
Also, the impact of high mobility is not evenly dispersed across the population, instead falling more heavily on disadvantaged children. Disadvantaged children—who are likely to come to school less well prepared than advantaged children—also move more frequently. These moves are unlikely to lead to any improvements in their schools. Higher-income parents can exercise more choice, taking schools into account when they move because of their ability to choose from a wider variety of housing opportunities. But restricted housing choices plus the concentration of high-mobility families leave lower-income children worse off.
Improving the education of disadvantaged children has been and should be an important policy goal. But the issue of school mobility highlights the difficulty of policy development. First, public schools should do more to take mobility into account. The highest mobility rates occur in large central cities, where poor children are likely to go to school. But, while decrying the problems of high mobility, many large systems have not aligned curricula and programs across schools to lessen the disruption of moving. Second, many people argue that improved schooling for poor kids requires more fundamental change, such as school choice, on the grounds that individual schools can develop innovative programs and that these programs can be one of the gains of more parental options.
The two policy options are not necessarily in conflict. Improved school choice mechanisms—ones that separate school attendance from the specifics of residential location—might stabilize schooling for some low-income children. If parents could maintain the same schools for their children even if forced by other circumstances to move, the achievement of low-income students (both moving and nonmoving) might improve. It is difficult to determine, however, whether this effect is sufficient to overcome forces that tend to increase the costs of family moves. As is often the case, developing the best policy outcomes involves trade-offs and experience.