JEFF JACOBY claims the tough 1998 gun control law not only didn’t prevent gun violence in the state but actually caused it to increase (“Crime soared with Mass. gun law,” Op-ed, Feb. 17). But neither Jacoby nor anyone else can prove the law did not reduce gun violence that would have occurred had the law not been enacted; it’s impossible to prove a counterfactual. Jacoby may think the law had no effect, and gun control supporters may think it did, but neither side can prove their point.
It is also illogical for Jacoby to assert that the subsequent increase in gun violence was caused by the law. To say, as he does, that the treatment prescribed by gun-control activists “may have yielded the opposite of the results they promised” is to mistake the temporal sequence of enactment of the law and increase in gun violence for a causal relationship between the two.