An Oregon study finds that grocery and convenience stores are more likely than liquor stores or drug stores to sell alcohol to young-looking 21-year-olds without asking for ID.

The PIRE Prevention Research Center sent decoys into alcohol outlets in 45 Oregon communities in 2005 to conduct the study. Researchers found that 38 percent of convenience-store clerks sold alcohol without asking for ID, compared to 14 percent of clerks at liquor stores or drug stores. Retailers who took part in the Oregon Liquor Control Commission's Responsible Vendor Program also were less likely to sell alcohol without checking IDs.

Overall, the decoys were able to buy alcohol without ID 34 percent of the time. Alcohol was purchased in 99 percent of the stores where ID was not requested, but only 13 percent of the stores where proof of age was demanded.

"[L]aw-enforcement agents should carry out more frequent compliance checks at the types of outlets that are most likely to sell alcohol to underage patrons," said Mallie J. Paschall, Ph.D., lead author of the study. "Programs like the Responsible Vendor Program may have a positive impact on protecting our young people."

The study was published in the journal Prevention Science.