In just about every state that increased beer taxes in recent years, teenage drinking soon dropped. The same happened in the early 1990's when Arizona, Maryland, New Jersey and a handful of other states passed zero-tolerance laws, which suspend the licenses of under-21 drivers who have any trace of alcohol in their blood. In states that waited until the late 90's to adopt zero tolerance, like Colorado, Indiana and South Carolina, the decline generally did not happen until after the law was in place.
Tax increases on alcohol and tobacco have been fairly common in recent years, allowing researchers to look for the crucial before-and-after effect that helps separate correlation from causation. Alaska, Nebraska, Nevada, Tennessee and Utah have all increased alcohol taxes since 2002. Georgia, Kentucky, Tennessee and Virginia -- tobacco-growing states all -- are among those that have raised cigarette taxes.
If drinking or smoking always seems to fall after a tax increase, then the case becomes far stronger. Looking across the states and taking into account all the other factors that can be measured, researchers have found that a 1 percent increase in the price of beer leads to a drop in teenage consumption of between 1 and 4 percent, Dr. [Sara Markowitz] said. For cigarettes, a 1 percent price increase causes roughly a 1 percent decline in smoking.