An abundance of liquor stores may be convenient if you're stocking up for a party, but a new study suggests that their presence may also spark a fair share of violence.

Researchers examined the relationship between newly issued liquor licenses and reported violent crimes in Seattle, Washington from 2010 to 2013. Starting in 2011, a new law shut down state-run liquor stores in lieu of allowing select private businesses to sell liquor, and the number of licenses increased substantially. After cross-referencing with census data, the researchers found for each newly licensed store or restaurant/bar in a neighborhood, there was a noticeable jump in both aggravated and non-aggravated assaults. These associations held even after accounting for other factors like the neighborhood’s level of poverty or average educational status, though the relative risk of violence did vary across the city.

"With alcohol availability increasing due to privatization, and with an already well-established relationship between alcohol and violence, it's critical to examine the impacts of these policies," said lead author Dr. Loni Philip Tabb, an assistant professor at Drexel University's Dornsife School of Public Health in Philadelphia, in a statement. "The increase for both aggravated and non-aggravated assault is significant and at a population level like this is a cause for concern. In urban areas, in particular, violence and alcohol already have an association, and neighborhood characteristics play a huge role in those violence rates."

Overall, each new license to a place where liquor is bought, such as large grocery stores, was associated with a 8 percent increase in aggravated assaults (which involve the use of a weapon), and a 5 percent increase in non-aggravated assaults. Similarly, the addition of a license to a place that can serve alcohol, such as bars, was associated with a 5 percent boost for both types of assault. In total, non-aggravated assaults jumped 42 percent. and aggravated assaults 74 percent, in Seattle during the time period following the law’s passing. according to the statement.

While the increases may be alarming, Tabb does believe there are ways to mitigate the impact of liquor privatization, which has been receiving support elsewhere in states like Pennsylvania, on violence. As well as lessons to be learned from Washington’s law.

"Washington state has very specific guidelines on the distribution of new off-premises licensing," Tabb explained in the statement. "For instance, new off-premises alcohol outlet licenses are to only be distributed to retailers with at least 10,000 square feet of space. Due to this limitation, smaller alcohol outlets, especially those in smaller convenience stores, are limited in their ability to gain additional licenses."

She added, "Other states that are deliberating privatization should consider specific limitations in the distribution of additional alcohol outlet licenses in neighborhoods that have already been shown to have concerns."

Ultimately, Tabb hopes her team’s research can highlight the rarely acknowledged consequences of these proposed laws as they begin to be debated elsewhere.

"Not only should these alcohol-related policies consider the financial impact of their implementation, but they should also consider the public health impact of significant changes in the alcohol availability landscape within neighborhoods," she said.

The findings were published last month in Spatial and Spatio-temporal Epidemiology.

Source: The spatio-temporal relationship between alcohol outlets and violence before and after privatization: A natural experiment, Seattle, Wa 2010–2013. Spatial and Spatio-temporal Epidemiology. 2016.