An increase in alcohol tax led to reduction in fatal car crashes.
Researchers from the University of Florida (UF) found that after Illinois increased taxes on beer, wine and spirits in 2009, there was a 26% fall in car crashes involving alcohol.
They report their findings in the American Journal of Public Health
The reduction in alcohol-related fatal car crashes was greatest among young people, say the researchers, who found in this group deaths fell by 37%.
In August 2009, the state of Illinois put up tax on beer by 4.6 cents a gallon, on wine by 66 cents a gallon and on distilled spirits by $4.05 a gallon. If all of this tax is passed on to the consumer, it adds 0.4 cents to the cost of a glass of beer, 0.5 cents to the cost of a glass of wine and 4.8 cents to the cost of a shot of spirits.
Introducing similar tax rises across the US could save thousands of lives, urges first author Alexander C. Wagenaar, a professor in the department of health outcomes and policy at the UF College of Medicine.
Inflation 'has eroded the effect of alcohol taxes'
If you take inflation into account, taxes on alcoholic drinks in the US have fallen substantially, helping to make the beverages significantly more affordable than they were 50 years ago.
The researchers suggest this has contributed to America's widespread drinking and driving problem.
In the US in the 1950s, the average person would have to set aside about half of their disposable income to afford more than 10 drinks a day. In 2011, 10 drinks a day is about 3% of the average person's disposable income. Prof. Wagenaar notes:
"If policymakers are looking to address dangerous drivers on our roads and reduce the number of fatalities, they should reverse the trend of allowing inflation to erode alcohol taxes."
Every year, around half a million people are injured and nearly 10,000 die in the US because of alcohol-related motor-vehicle crashes.
Decrease in fatal crashes was due to tax changes and not other factors
For their analysis, the team used data on fatal crashes in Illinois between January 2001 to December 2011 recorded by the National Highway Traffic Safety Administration.
They examined the patterns of fatal crashes in the 104 months before and in the 28 months after the new alcohol taxes were brought in.
The details in the Illinois car crash data allowed them to analyze the effect of the tax change in terms of driver's age, gender, race and level of blood alcohol measured at the time of the fatal crash.
For the study, the team defined a blood alcohol level of under 0.15% as impaired driving, and above this level as drunken driving.
A blood alcohol level of 0.15% is roughly the level an average adult has after drinking six alcoholic drinks in 1 hour.
The team adjusted the results to take into a number of other factors than can influence motor vehicle crashes, including traffic safety programs, economic conditions and the weather.
In their analysis they compared the number of alcohol-related fatal crashes with those not involving alcohol in the same period, for Illinois, and also compared the results with a similar analysis of crashes in Wisconsin, a state that had not introduced any tax changes.
The adjusted results and interstate comparisons confirmed that the decrease in fatal car crashes was due to the tax changes and not other factors.
The researchers suggest a reduction in disposable income - as a result of the Great Recession - may have contributed to the larger than expected effects of such a modest tax increase.
Results contradict belief that heavy drinkers ignore tax rises on alcohol
The researchers found the reduction in crashes involving alcohol-impaired drivers (22%) was very similar to those involving extremely drunken drivers (25%).
Prof. Wagenaar concludes:
"While our study confirms what dozens of earlier studies have found - that an increase in alcohol taxes reduces drinking and reduces alcohol-related health problems, what is unique is that we identified that alcohol taxes do, in fact, impact the whole range of drinking drivers, including extremely drunk drivers."
He says this finding has "powerful implications for how we can keep our communities safer," and contradicts what many economists say - that heavy drivers are less likely to respond to tax changes.
Meanwhile, Medical News Today recently reported a study by researchers at the University of Michigan Injury Center that found fitting a breathalyzer interlock system to new cars could prevent 80% of drunk-driving deaths. The system is designed so that before they can start the car, the driver has to breathe into the device, which is fitted on the dashboard and measures their blood alcohol content (BAC). If their BAC is above the legal limit - which varies by state - the vehicle will not start.