There is not a single study that shows gun buybacks have any positive effects, but there are several studies that show buybacks are not effective in reducing gun violence. Worse, buybacks have some serious negative impacts.
--At best they recover only a tiny fraction of the available gun stock; not enough to even put a dent in the additions to the gun stock—especially now with sales going through the roof thanks to all the great sales people—Obama, Feinstein, etc.
--It’s a good chance for people to off-load crumby guns they would not fire and buy at least one good one that they might actually use.
--The guns surrendered are extremely unlikely to ever be used much less misused, by the low risk people who surrender them.
--Anonymous turn-ins for some valuable consideration provide a great incentive to steal guns. --What if Aunt Mary turns in deceased Uncle Joe’s gun? What if that gun turns out to be worth $2,000-$3,000 or more? What if Aunt Mary could really use that money? Doesn’t this sound sort of like an unethical elder abuse scam?
One of many authoritative sources—22 years old and still accurate:
Kleck, Gary. Targeting Guns: Firearms and Their Control (1997).