"Usually people think that liquor stores define a neighbourhood's alcohol consumption, but we didn't find any relationship between them and problem drinking among the adult population in California," study author Khoa Truong, PhD, said.
Researchers said that instead, their findings point to so-called "minor-restricted establishments" -- adults-only bars and nightclubs -- as having the most consistent and sizeable effects on adult problem drinking, even though they accounted for only about six percent of the total number of alcohol retail licenses in the area studied.
The research team said that after accounting for one's education level, income, race, and neighbourhood sociodemographic characteristics, they found that a higher number of minor-restricted establishments located within one mile from someone's home is associated with that person's higher likelihood of binge drinking and consuming excess alcohol.
"If the number of minor-restricted establishments increases, on average, from zero to two in a neighbourhood, the prevalence of heavy episodic drinking in the past 30 days would increase from 11.1 percent to 14.3 percent among women and from 19.6 percent to 22.0 percent among men; and prevalence of riding with a driver who perhaps had too much to drink would increase from 2.9 percent to 4.1 percent among women and 4.0 percent to 5.5 percent among men," Truong said.
Researchers said that they were not surprised with the results because bars, taverns, and night clubs, especially those that do not allow minors, are where social and cultural norms are more likely to accept, if not encourage, excess drinking.
The new study has raised questions about the effectiveness of policies that target alcohol sales in general, such as a regulation in counties in California that limits the sale of alcohol licenses based on population numbers.
For example, California imposes a moratorium on the issuance of alcohol retail licenses when the ratio exceeds one on-sale general license for each 2000 persons and one off-sale general license for each 2500 persons.
Truong's study has indicated that limiting the total number of alcohol licenses is not as effective as targeting certain types of licenses, namely those for minor-restricted drinking establishments.
"What's usually happening is that alcohol outlets are regulated at broader environments. It turns out that the action happens within a micro environment," Truong said.