Threshold Effects and Neighborhood Change

In this article, the authors assemble, synthesize, and assess the disparate, fragmented literature concerning thresholds related to neighborhood change. They find several theories of neighborhood change that imply the existence of thresholds and identify six alternative mechanisms for generating threshold effects. They critically examine empirical evidence on changing neighborhood racial group composition, income group composition, social and economic conditions (criminal activity, friendship, teen child-bearing, marriage, educational attainment, employment and earnings, social relationships, health, and welfare dependency), and housing investment. The authors find evidence of threshold effects in dynamics of all these neighborhood attributes. The possibility of identifying thresholds provides guidance to planners for spatially targeting reinvestments to those neighborhoods approaching or past critical thresholds. Future research needs to devise careful empirical tests designed to distinguish the alternative mechanisms producing thresholds and ascertain the generality of findings summarized in this review.