This article was published in, and the following abstract copied from Substance Use and Misuse.

This study addresses the problem of operationalizing neighborhood boundaries by investigating foster care entry risk at three spatial scales. Foster care entries from a California county between 2000 and 2003 (n = 3,311) are geocoded to each of the three scales (N = 46 zip codes, 320 census tracts, and 983 block groups). Exploratory spatial data analysis is used to compare spatial autocorrelation of entry rates among scales. Results suggest that depending on how neighborhoods are defined, the geographic pattern of foster care incidence changes. Implications for accurately targeting services to high-risk neighborhoods and future research directions are noted.