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Mystery Shoppers: Can they prevent sales of alcohol to minors?

Clerks and servers at alcohol establishments often fail to check ID to make sure that purchasers are 21 or older.  Sales of alcohol to minors can increase the risk of a wide range of alcohol related problems, both short term (impaired driving, alcohol poisoning) and long term (alcohol addiction).  Using mystery shoppers to provide feedback to the clerks and servers and to their managers is one approach to improving age verification.  A recent study by researchers at the Prevention Research Center of the Pacific Institute for Research and Evaluation, along with partners from Boston University and the Responsible Retailing Forum, found that this strategy can improve the chance that the ID will be checked. 

Mystery shoppers attempt to purchase alcohol and then provide feedback on whether the clerk or server asks for ID.  The mystery shoppers are old enough to purchase and consume alcohol legally, but young enough to trigger a request for ID.  Mystery shop programs typically provide owners and managers with written feedback on staff performance.  They can also provide immediate feedback to the clerk or server, reinforcing appropriate ID-checking and, if staff members fail the mystery shop, citing the need to check IDs for all young-appearing customers.

The study included 557 on- and off-premises alcohol outlets located in 16 communities in four states in the U.S. (California, Massachusetts, Texas, and Wisconsin).  The researchers randomly sampled 324 on-premises serving establishments (such as bars and taverns) and 313 off-premises retailers (such as liquor and grocery stores) to be invited into the study. 

The mystery shopper program included monthly visits to the outlets after which clerks and servers received immediate feedback to reinforce age verification.  Managers received monthly reports on whether their staff checked IDs. 

ID checking increased from an average of 80% during the baseline to an average of 90% during the initial intervention period, achieving 96% by the end of the program. 

Overall, off-premises outlets were somewhat less likely to check IDs (83%) than were on-premises outlets (85%).  Both types of outlets, however, increased ID-checking rates during the intervention periods, each achieving 93%-96% pass rates by the end of the program.

Lead study author, Dr. Joel Grube stated, “This study provides evidence that a responsible retailing program employing young, legal-age mystery shoppers who attempt to purchase alcohol and then provide feedback on whether the clerk or server asks for an ID can improve ID-checking performance.  This gives outlets a very valuable tool to make sure that their employees follow the law and help keep our young people safe.”

From the perspective of regulators, police, prevention advocates, and the retailers themselves, compliance with underage sales laws is an important goal.  Responsible retailing programs that use mystery shops can assist retailers in complying with the law and play an important role as part of a comprehensive alcohol control system that includes enforcement and sanctions for retailers who sell alcohol to minors.

Source:  Grube, J.W., DeJong, W., DeJong, M., Lipperman-Kreda, S., & Krevor, B. (in press). Effects of a responsible retailing mystery shop intervention on age verification by servers and clerks in alcohol outlets: A cluster randomized cross-over trial. Drug and Alcohol Review