One of the arguments for legalizing dope is that, given the fact that people are going to use one kind of intoxicant or another, we'll be better off, and safer (on the road, for example), if they're stoned rather than plastered. Essentially, the theory is that, to some significant extent, we'll trade alcohol consumption for dope smoking, and that the dopers will be more laid back, and take it easier, than the drunks.
Prof. Doug Berman has made this argument numerous times.
It's an empirical proposition, of course. We can test it by looking to the states in which recreational dope is legal (under state law), and thus more readily available. (The additional advantage, we are told, is that legalized dope will be regulated, and thus less subject to adulteration and other perils of a black market product).
Q: So how are things working out in the largest of the legalized pot states, Colorado? Is alcohol consumption lower than in states where dope remains illegal?
A: See this Denver Post article, "Colorado Stands Out for Consuming Drugs, Alcohol -- High levels of pot consumption expected, but Colorado stands out for other inebriants, too."
Oh well.
Interesting, but these kinds of state v. state comparisons have limited probative value for determining causation, particularly when they are one-time snapshots. Data showing changes over time periods spanning changes in policy tend to be more informative.
In the death penalty debate we often hear the argument that states without the death penalty tend to have lower murder rates, therefore if the states with the death penalty got rid of it, their rates would go down, not up. It does not follow. States that have abolished the death penalty and have low murder rates today typically already had low rates before they decided they could do without the death penalty.
-- For sure these sorts of data have limited value for proving causation. They have more value, however, for doubting it.
If, as has been argued, there is a trade-off between pot use and excessive drinking, it would not NECESSARILY be the case that, in a snapshot survey, one would see low levels of drinking where there are high levels of pot use. True enough.
It would be odd, however -- if a trade-off actually exists -- to find very high levels of pot use AND very high levels of drinking.
Now to say that something is odd is not necessarily to say it's untrue. But it is to cast its truth into question in a way that had not theretofore existed.
-- The "states-without-the-DP-have-lower-murder-rates" argument is baloney for an obvious reason not involving the logical fulcrum of trade-off's: States without the death penalty historically (e.g., Minnesota, North Dakota, Vermont) have tended to need it less because their murder rates were lower to start with (although this is changing fast in, for example, Illinois).
By similar reasoning, the country as a whole is using the death penalty less over the last 20 years because the national murder rate has fallen precipitously; there is less of a disease in need of a harsh cure. It does not mean that the country has started to disapprove the DP. The level of support is less than it was in the high-murder 1990's, but remains at very high levels for an issue this contentious.
Bill, there are many social and legal factors that influence use rates (and reporting rates) for a wide range of drugs, and these factors may take decades to develop and change. For this reason and others, looking at Colorado only a short time after marijuana legalization does not resolve whether, over time, there will be a substitution effect between alcohol and marijuana.
Moreover, marijuana's possible substitution for alcohol is only one of a number of factors that might provide support for legalization. The more compelling ones, in my view, involve enhancing personal freedom, generating jobs and private/public revenues, and reducing all the social harms that come from black markets and prohibition enforcement.
Funny how Doug abandons the "best data available" argument when it does not support his position.
Suddenly, the cause is all of these unmeasured factors.