Since adolescents typically spend a good deal of time away from their homes, explanations of neighborhood influences involving peer-based “epidemics,” role models, schools, and other neighborhood-based resources would appear to be more relevant for them than for younger children. However, interactions between preschool children and their kin, neighbors, religious communities, child care, and health systems suggest that neighborhood influences may begin long before adolescence (Klebanov et al., 1997).
Despite ample theoretical reasons to suspect that neighborhood conditions influence development and behavior, the task of securing precise, robust, and unbiased estimates of neighborhood effects has proved remarkably difficult (Duncan and Raudenbush, 1999; Manski, 1993). One important difficulty is measuring a neighborhood's social organization, institutions, and levels of violence. A subtler problem arises from the fact that families are not randomly allocated to their residential neighborhoods, which may lead researchers to mistakenly attribute effects to neighborhood factors that are really caused by unmeasured differences in the children's parents. The major challenge facing those who seek to understand how family contexts affect early development is that parents usually select these environments. They decide where to live, where and how much to work, and whether and when to place their babies in child care and which child care settings to use. Thus, effects on children that are ascribed to such factors as neighborhoods may, in fact, really be effects of parent selection. Compounding this problem is the high mobility that characterizes families with young children. Nearly one-fourth of young children ages 1 to 5 move to a new home during the course of a year, with moves only slightly more common among black and Hispanic than among white young children.
A final problem is that of isolating the effects of conditions in the worst urban neighborhoods from effects caused by the more general range of neighborhood conditions. Representative population surveys typically draw relatively few families from high-poverty urban neighborhoods. Analysts using these surveys base estimates of neighborhood effects on relative differences among more advantaged, mostly white families and children. If neighborhood conditions matter more for disadvantaged than advantaged children, as some have found (Cook et al., 1998), then studies of neighborhood effects based on broad population samples may miss an important part of the story.
Most broad-based neighborhood studies rely on data gathered in the decennial census. Every 10 years, the Census Bureau provides information that can be used to construct neighborhood-based measures, such as the