mom2and
February 26, 2015, 9:55pm
48
From the US Dept of Treasury, National Highway Safety:
Conclusions
MLDA 21 laws clearly reduced youth drinking and driving. They appear to have done so both by reducing youth drinking directly and by encouraging youth to separate their drinking from their driving.
MLDA 21 laws reduced youth drinking both by reducing alcohol availability and by establishing the threat of punishment for alcohol use. Neither works particularly well in practice, as youth still can obtain alcohol relatively easily and underage drinkers are highly unlikely to be detected and punished. But both have had some effect.
But MLDA 21 laws probably had other effects beyond the straightforward prohibition and attempted punishment of alcohol use by youth. As listed in Chapter IIIB, 11 states have had MLDA 21 laws since the repeal of prohibition. These states also saw substantial reductions in youth drinking and driving after drinking in the 1980s. Furthermore, youth driving after drinking decreased more than youth drinking.
This suggests that MLDA laws may have helped influence youth attitudes about drinking and driving. The principal reason for raising the drinking age to 21 was to reduce traffic crashes. Some youth and some parents may have consciously or unconsciously absorbed some of these beliefs: that youth drinking is not a problem unless it results in dangerous actions, of which by far the most dangerous is drinking and driving. Underage drinking is generally accepted, but underage drinking and driving is not. The widespread debate over the legal drinking age also may have had some “spillover” effect in states where MLDA 21 was already in place.
However, the observations that youth drinking and driving decreased substantially more than youth drinking, and that youth drinking and driving after drinking both decreased in states which had MLDA 21 laws throughout the 1980s, suggest that MLDA 21 laws were not the only influence on youth drinking and driving during this period.
One big difference is that 18-20 yos could not go to bars, which generally require driving longer distances than going to a neighborhood friend’s house. At some point in that period, the consequences for drinking and driving also became much stricter. It is hard to determine which had the most influence on declines in drunk driving.