Gun-control advocates in the wake of the Sandyhook school shooting have used a particular statistic over and over again: “As many as 40 percent of guns are purchased without a background check.” While President Obama, Vice President Biden, the New York Times, the Wall Street Journal, USA Today and many others have used the “fact” repeatedly, it is false, says economist John Lott in the National Review.

The “40 percent” claim misrepresents the actual number that was reported — 36 percent — which is still above the accurate number, says Lott.

The number 36 percent actually comes from a Clinton-era survey of 251 gun sales that occurred before the Brady Act required mandatory background checks. The survey asked buyers if they thought they were buying from a licensed dealer; many buyers who did not believe the seller was licensed actually bought from small dealers and did not know they were licensed.

Access to guns is also much more limited since many small dealers have been forced out of business. After accounting for guns that were bought, traded, rented, issued for a job or won through raffles, 85 percent went through federally licensed firearms dealers, meaning just 15 percent of the 251 gun sales were transferred without a background check. Lott says that if the same survey were performed today the numbers would likely be in the single digits.

President Obama claimed that background checks have kept 1.5 million people from purchasing a weapon in the last 14 years but failed to explain that number reflected only initial denials.

According to the Bureau of Alcohol, Tobacco and Firearms, 94 percent of those initial denials were dropped after preliminary reviews, almost all of the rest were dropped after extended reviews and only 62 people, or just 0.1 percent, were prosecuted for attempting to purchase a weapon.