Immediately following the ordinance, the average weekly number of alcohol-related arrests increased from 9.3 to 16.3. Since over 21 arrests also increased, the change cannot be attributed solely to the new ordinance; indeed, additional police resources were deployed in a deliberate attempt to change the drinking culture. Of course, since the arresting officer cannot generally detect residency prior to arrest, arrest data still represent a geographically unbiased sample of bar patrons and can be used to explore changes in the mix of patrons.