Although the media’s response to the tragic massacre of Congresswoman Gabrielle Giffords and others in Tucson, Ariz. on Jan. 8 focused largely on right-wing rhetoric, the incident has also renewed calls for tougher gun laws. A bill introduced on Jan. 18 by U.S. Rep. Carolyn C. McCarthy (D., N.Y.), which is cosponsored by 65 congressmen, is similar to the Clinton-era Federal Assault Weapons Ban (AWB) that the Republican Congress allowed to expire in 2004. The Obama administration voiced its support for reinstating the AWB during its first hundred days, and Newsweek reports that the White House is soon to unveil “a new gun control effort.” The trouble is that the ban would not have prevented the Tucson shooting, and even if it had, this by itself would not be a valid reason for its reinstatement.

The AWB, enacted in 1994, imposed a 10-year ban on the manufacture, transfer, or possession of 19 models of semi-automatic assault weapons-military-style guns for which the trigger is pulled for each shot fired. It also banned the transfer or possession of magazines that hold more than 10 rounds. Importantly, the law exempted weapons and magazines lawfully possessed prior to the date of enactment.

Contrary to what has been reported by gun control advocates and much of the media, the crime perpetrated by crazed Tucson resident Jared Lee Loughner is very unlikely to have been prevented by the AWB. The assailant’s weapon, a nine-millimeter Glock 19 pistol with 31-round magazines, was not banned by the law. What was banned was the transfer or possession of new large-capacity magazines, which, as Kevin D. Williamson explains in National Review, remained commonplace during the AWB. Harvard economist Jeffrey A. Miron notes in Businessweek that Loughner could have carried out his attack with high-capacity magazines sold before the ban took effect, or purchased one on the black market. Or he could have simply carried multiple (legal) guns so as to fire continuously. The AWB might have made Loughner’s rampage a bit more difficult, but it would hardly have stopped him.

The focus on the impact the AWB would have had in the Loughner case is misguided for another reason: Gun policy should aim to minimize aggregate crime. How a law operates at the micro level, as in the Tucson massacre, is relevant only insofar as it helps us understand the law’s broader impact. The appropriate question to ask in deciding whether to reinstate the AWB is not whether it would prevent certain isolated incidents, but the extent to which it would reduce overall crime, and whether this reduction outweighs the cost of imposing such a ban.

Academic literature does not provide consistent evidence that such restrictions reduce crime, and analyses frequently conclude that they have little if any effect. With respect to the AWB, a 2004 University of Pennsylvania study noted that assault weapons were rarely used in gun crimes before the ban and that the reduction in violence that would result from renewing the law, while nontrivial, was likely to be “small at best.”

Saving even one life would be nontrivial, but whatever reduction in violence accrues from the law must be weighed against its associated costs. Permitting semiautomatic weapons for the sake of recreation, or even the principle of constitutional rights, might appear ridiculous if it comes at the cost of human life. What is not ridiculous is the fact that enforcing any law requires resources; in this case, the state must pay for the prosecution of lawbreakers in terms of the training and wages of law enforcement personnel and court costs. Given the mediocre record of gun control in general and of the AWB in particular, these funds might be better spent improving enforcement of existing gun laws, treating victims of gun violence, educating the public about gun safety, or serving unrelated purposes. Given what we know about Jared Lee Loughner, they might be better spent on mental health services. Furthermore, any attempt at gun control is likely to give rise to a black market, which, as in the illicit drug trade, breeds violence inasmuch as market participants cannot resolve disputes through the judicial system. And stricter controls than the AWB might limit the ability of law-abiding citizens to defend themselves against criminals.

Perhaps the most significant cost of this or any gun control law is that it opens the door to further restrictions that may be less reasonable. The best evidence of this is the United Kingdom, which at the beginning of the twentieth century had hardly any restrictions on the right to arms and now imposes virtually outright prohibition. The transition to the control regime was fueled by media focus on isolated gun crimes , which politicians used as justification for ever tighter restrictions.

While it goes without saying that the government should try to prevent incidents like the Tucson shooting, citizens should realize that some degree of gun violence is inevitable regardless of laws Congress passes, and that public policy faces tradeoffs between gun crime reduction and other objectives. Whatever policy the government adopts should be an attempt to maximize aggregate living standards with available resources, and should not be a visceral reaction to one unfortunate event.

Peyton R. Miller ’12 is a government concentrator in Winthrop House. His column appears on alternate Tuesdays.