The greatest harm is associated with multiple moves. Children who moved three or more times in the first few years of school show the most negative associations. However, there is good reason to regard multiple moves over time not only as a clearly defined variable but also as a marker for a cluster of developmental problems and other risk factors. A high rate of mobility could be a contributing factor on its own, but it is consistently accompanied by other risks, such as family disruption, homelessness and economic disruption. It is difficult to disentangle the factors; for example, if a highly mobile child is also frequently absent from school, is that because of the mobility, or is it a sign of other underlying problems in the family?
High mobility in schools affects everyone. The best available evidence suggests that all children in highly mobile schools experience negative effects, even if they do not move themselves. The churning of students is likely to make instruction more difficult, to interfere with the continuity of programming, to necessitate more review, and to disrupt social networks.
Given this picture, Raudenbush said, “it is time to get past the question of whether moving by itself has an average effect in the total population of U.S. families.” Reasons for moving and circumstances are so heterogeneous that a fresh research agenda is needed to focus on the subgroups most likely to make the sorts of moves that have negative effects. The research priorities he listed are rigorous evaluation of interventions designed to: stabilize housing and therefore to prevent excessive residential mobility, to support school stability when many short-distance moves affect students, and to protect children against the negative impacts of residential and school mobility. Promising interventions need to be evaluated to make sure they can be faithfully implemented and their effects should be assessed, preferably using randomized experiments. Rent subsidies, adjusting school policies to help children stay in a school even when they move a short distance, coordination of instruction across local schools, coordination of family services, perhaps using the school as a central source—all look like promising approaches that merit detailed evaluation, he observed.
With that overview on the table, several presenters offered their perspectives on the major research questions, the methodological approaches they would use to answer those questions, and the strengths and limitations of those approaches.