Dear Cecil: Several years ago I turned in a gun for cash during a police buyback program. For me it was a practical exchange. But do these programs have any impact? Are communities with buybacks experiencing less gun-related injury and/or crime? Tom in San Jose

Cecil replies:

Generally speaking, no. Gun buybacks are like a congregation declaring their church a nuclear-free zone. No doubt it makes them feel virtuous. But the practical impact is nil.

Gun buyback programs operate on the premise that fewer guns in society means fewer crimes, suicides, and accidents — or at least fewer deaths from those causes. Many cities have offered buybacks, but studies of their effectiveness almost always find no impact. Examples:

Neither St. Louis nor Seattle saw reductions in murders or assaults with guns after enacting buyback programs.

Boston’s sizable gun buyback programs coincided with a decrease in the city’s crime rate, but crime decreased at similar rates in cities without buybacks.

A multiyear study of Buffalo’s gun buyback programs found a reduction in armed robbery using guns, but no significant difference in other gun-related crime.

A meta-analysis of gun-related-crime intervention methods found buybacks had the least effect.

So why don’t gun buyback programs work?

Most U.S. programs are local and scattered, as opposed to national or even statewide. Since guns can easily be transported, isolated efforts amount to bailing the ocean.

And bailing with a teaspoon at that. Typical haul per buyback: 1,000 guns. Total guns in the U.S.: 300 million. To put it another way, in 2011 there were 10,000 gun homicides. Given the number of firearms, that means any particular gun has a 1-in-30,000 chance of being involved in a killing. On the unlikely assumption that the number of gun deaths is strictly proportional with the number of guns, the typical buyback reduces the death toll by one-thirtieth of one corpse.

Some take advantage of gun buyback programs to dispose of useless weapons. In Sacramento a quarter of the guns collected were broken; in Seattle a sixth were.

Buybacks tend to yield a lot of rifles and shotguns (aka long guns), small-caliber handguns, and other firearms not commonly used by criminals or in suicides. In Boston’s 1993 and 1994 buyback programs, only 2 percent of the guns retrieved were large-caliber handguns. Despite substantial new incentives for handguns, in 2006 this figure increased to only 26 percent. A Sacramento study found 63 percent of handguns turned in were small-caliber.

No one seriously expects criminals are to turn in a gun and deprive themselves of a tool of the trade. Upshot: buyback programs take low-risk weapons away from low-risk individuals.

Attempts to improve the effectiveness of buyback programs have met with little success. Unhappy with the response to its earlier efforts, Boston took several steps to improve the impact of the 2006 buyback — offering a $200 Target gift card for each handgun (but none for long guns) and providing alternate drop-off locations that weren’t in police stations. However, it also required everyone turning in a gun to present ID (to keep out-of-staters from cashing in worthless old handguns). Result: the turn-in numbers for 2006 were at best no better than in ’93 and ’94.

Some will say we need a national buyback program. Ignore the fact that such a program is politically impossible in the U.S. — would it work? To get an idea we can look to Australia, which banned some long guns following a 1996 massacre in which 35 were killed and 23 others wounded by a gunman using assault rifles. As part of the ban, the government launched a nationwide program offering market value for the newly prohibited weapons. The take was 650,000 guns, about 20 percent of the country’s firearms.

Granted, Australia was a special case — an island nation can control its borders more easily than most places. More important, the buyback was attached to a gun ban — those who hung on to illegal weapons faced criminal charges.

Even so, the impact of Australia’s program is disputed. One study found no benefits at all, while another claimed the homicide rate decreased 5 to 10 percent. Gun-related suicides decreased significantly, but the overall suicide rate didn’t.

True, yet another study credited the Australian buyback with a 74 percent decrease in the gun suicide rate and a 35 to 50 percent decrease in the gun homicide rate. But the evidence for attributing the gun homicide drop to the buyback is unpersuasive. Gun and non-gun homicides fell at the same rate between 1995 and 2006. While gun homicides were somewhat more common than the non-gun kind 30 years ago and are less common now, the reversal happened circa 1988, well before the buyback.

This doesn’t mean gun buybacks do no good whatsoever. They put a few bucks in the pockets of people like you who want to get rid of unwanted firearms, and conceivably they reduce accidents from “unloaded” guns lying around the house. But overall, do they reduce gun killings, or killings period? Don’t kid yourself. No.

Cecil Adams

Send questions to Cecil via cecil@straightdope.com.