On Thursday's Andrea Mitchell Reports on MSNBC, the host cherry-picked a 20-year-old flawed study to push the claim that 40% of all gun sales are made without background checks.

Mitchell was hosting Sara Brady the chair of the Brady Campaign and wife of Jim Brady the spokesman for President Reagan who was shot in the head during an assassination attempt on the President and Dan Gross President of the organization. She introduced her guests with:

It's been 20 years since the passage of the Brady Bill that established background checks for gun purchases in stores. But the Brady campaign to prevent gun violence is looking to build on that landmark legislation and close all those loopholes that still allow for 40% for all gun purchases in the U.S. to occur without any background checks. Joining me now is the one and only Sara Brady, chair of the Brady Campaign To Prevent Violence and Dan Gross, the campaign's president, Sara, it's great to see you again.

Later in the interview Ms. Brady referred to the same study:

Well, talking about guns doing a background check. We're not talking about touching the gun. It's the people we worry about. You know that the term NRA uses “guns don't kill people, people kill people,” which is exactly why we need to do background checks on people, to make sure they are not prohibited. But now 40% of the guns are not covered.

According to John Lott, economist and gun expert, the 40% figure comes from a very small study covering purchases during 1991 to 1994.

Not only is that two decades-old data, but it covered sales before the federal Brady Act took effect on February 28, 1994. The act required federally-licensed dealers to perform background checks. The 40% number (actually its 36% rounded up) is for all gun transfers, not only sales. Lott reports the vast majority of these transfers involved within-family inheritances and gifts.

If only sold guns were counted, 84% were reported to have gone through licensed gun dealers. But even that number is probably depressed, as there were biases in the survey.

For example, two-thirds of federally licensed dealers at the time were so-called “kitchen table” dealers who sold gun out of their homes and most buyers surveyed were likely unaware these individuals were indeed licensed. By the way, that survey also found that all gun-show sales went through federally licensed dealers.