"Why Economists Tend to Oppose Gun Control Laws"
Let's start with the relationship between means and ends. The shooter had his ends: he wanted to kill many people, and he wanted it to be visible and spectacular. He also had his means: guns and bullets. He engaged in forward-looking behavior: he purchased the guns, bullets, chains, locks, and video equipment well in advance. He taped himself in advance explaining what he was going to do and why he was going to do it.
Now let's consider gun control. Many people argue that if the shooter did not have guns and bullets, he would not have been able to shoot all of those people. This is surely correct. However, from that, they infer that if he did not have guns and bullets, he would not have been able to kill all of those people. This is a whole different question.
As Mises.org readers know, in economics, we discuss the idea of substitutes. These are goods that can be used to replace each other such as Coke vs. Pepsi, contact lenses vs. eyeglasses, Macs vs. PCs. When a person has ends, a person can select among different means to achieve those ends. These different means are substitutes.
Cho wanted to kill many people, and he wanted it to be visible and spectacular. To that end, he purchases guns, bullets, chains, and locks (to prevent survivors from escaping). Would gun control have prevented this? Or would Cho ÷ who apparently planned this attack for weeks, based on the fact that he acquired guns, bullets, chains, and locks for weeks - have used substitute goods?
What would Cho's substitutes have been? What others means are there by which he could engage in mass murder? Well, he could have purchased a knife, although that is probably a weak substitute for guns and bullets in achieving his ends. He has to be right next to his victim, and he might be defeated in personal combat by another person. Likewise, he could not kill a lot of people in the same time frame, and it would not be as spectacular. . . .