Lovenheim M.F., Slemrod J. ‘The fatal toll of driving to drink: the effect of minimum legal drinking age evasion on traffic fatalities’. Journal of Health Economics: 2010, 29, p. 62–77.
This meticulous analysis reveals that increasing the legal drinking age can cause traffic accident deaths if underage drinkers can drive to a nearby jurisdiction with a lower age limit to legally buy and drink alcohol, returning too intoxicated to drive safely. The message is that such limits need to be uniform to have the maximum beneficial impact.