Public Opinion on Marijuana Legalization: What the Data Say
By Bryan Caplan
I’m all in favor of speculation on questions where the data are unclear or non-existent. But if excellent data exists on a question of interest, we should consult it. The General Social Survey has been asking Americans “Do you think the use of marijuana should be made legal or not?” for decades. (Variable identifier GRASS). Tyler puts great emphasis on the parent/non-parent divide, and Megan McArdle backs him up. Is the GSS on their side?
They definitely get the sign right. Here are the results from a simple regression of opposition to legalization on year, age, education, and parental status:
All else equal, people with kids are 8 percentage-points more opposed to legalization than people without kids. The effect is comparable to 27 years of trend cultural change, 27 years of age, or 6 years of education.
But throwing in more variables sheers the effect of parental status – and gives us better yardsticks for comparison. Here’s what happens if you add controls for ideology, church attendance, and gender:
Notice: Adding a few controls roughly halves the effect of having kids. The gap between parents and non-parents is smaller than the maternalistic gap between women and men. Parenthood matters less than a single step on the GSS’s 7-point ideology scale, and much less than two steps on its 8-point church attendance scale.
P.S. I must report with smug satisfaction that most of the apparent effect of education is a disguised effect of IQ. Intelligence once again makes people think like economists.