The Effect of Block Size on Crime: Testing Jacobs' Suggestion on the Need for Small Blocks

• In Event: Place and Spatial Conditions: Advancing Existing Evidence and Measurement

Abstract

This study examines whether block size influences spatial patterns of crime. Jacobs (1961) suggested small blocks are essential to securing urban safety by promoting pedestrian activities and increasing “eyes on the street.” Despite its theoretical importance, the effect of block size on crime has been largely overlooked in existing research, which has focused more on other physical environments like street networks and land use.
Adopting the area-weighted average perimeter (AWAP) measure as a proxy for block size, this study investigates its relationship with robbery, felony assault, burglary, larceny, and larceny of motor vehicle in New York City census block groups (2017–2019), controlling for other variables. Negative binomial regression results indicate that AWAP is positively associated with all types of crimes, suggesting larger blocks increase crimes.
Drawing upon Jacobs’ notion that physical environments interact to shape urban safety and that opportunities to turn corners must be frequent, this study also explores the moderating effects of intersection density on AWAP. Results show that high intersection density reduces the criminogenic effect of block size across all crime types, suggesting more permeable environments enhance urban safety. Findings contribute to theories and crime prevention strategies by highlighting the role of block size.

Authors

• Jinuk Jeong, City University of New York, Graduate Center / John Jay College of Criminal Justice

• Jisoo Cho, Graduate Center / John Jay College of Criminal Justice, City University of New York

• Kevin Wolff, John Jay College of Criminal Justice