Researchers employed a triple-difference (difference-in-difference-in-differences) model that compared reported crime before versus after the change in alcohol policy, Sundays versus other days of the week, and the fraction of liquor stores affected versus not affected by the repeal. The authors utilized crime-incident data in Philadelphia between 1998 and 2011.
Results show that the repeal was associated with a significant increase in total and property crime incidents occurring around Sunday-open state liquor stores in low socioeconomic status neighborhoods. There was no consistent evidence of displacement of crime to nearby areas. This is the first triple-difference alcohol study that attempts to isolate the micro-spatial effects of a shift in alcohol availability on local crime patterns, and it shows that the repeal of Sunday alcohol-sales restrictions may increase crime in poor urban areas.