Norwegian study links longer bar opening hours to increased violence

A study of Norwegian cities suggests that suggest that a one-hour extension of bar closing hours led to an increase of an average of 20 violent cases at night on weekends per 100,000 people per year. This represents an increase in violence of approximately 16 percent.

http://www.eurekalert.org/pub_releases/2011-11/w-nsf112811.php