Like public health care, Canada’s tight gun-control laws help distinguish the country from its powerful neighbor to the south. But as Canadians commemorated the 20th anniversary of one of the country’s most notorious shooting sprees on Sunday, their Parliament was on course to eliminate one of its most significant gun-control measures.

A long-gun registry, which requires the registration of rifles and shotguns, emerged largely from public revulsion over the massacre in 1989.

What should libertarians think about gun control laws, like long-gun registration in Canada, that inconvenience purchasers but do not, by themselves, prevent responsible persons from owning guns?

My view is that the direct costs of such laws are small, but so are the direct benefits.  It is possible that registration occassionally allows police to solve a crime or remove a gun from an unstable situation, but the number of such instances is rare.   Thus, it is hard to get excited about such laws, for or against, if one considers only their direct impact.

The crucial question is slippery slopes.  If mild controls like registration or background checks pave the way for more serious laws - bans on some or all guns - then in my judgment mild laws cause substantial harm.

What does the evidence say about slippery slopes?  Most countries had no gun control laws a century ago, and their initial laws were "mild."  Yet over time gun control has expanded enormously, and in some countries it amounts to virtual prohibition.   This is consistent with slopes being slippery.

Given this, and my view that mild laws rarely generate direct benefits, I oppose all gun control laws, including mild ones.