Proponents of stepped-up background checks on gun buyers assert that up to 40 percent of gun sales do not involve a federally licensed dealer and therefore are exempt from the current federal requirement for a background check. Opponents say the figure is far too high. Philip Cook of Duke University and Jens Ludwig of the University of Chicago, whose research produced the 40 percent figure, write for the National Review that, “We don’t know the current percentage, not does anyone else.”
Cook and Ludwig say that if the true figure turns out to be lower, that strengthens the case for a universal background check. “A universal background check is a good idea only if it can pass a cost-benefit test,” say Cook and Ludwig. “The benefits in this case are measured in lives saved from prevented homicides and suicides. The costs are the potential fees and inconvenience to buyers who would have to arrange a background check by a licensed dealer before buying a gun from a non-licensed seller.” If in fact “a smaller number of gun transactions occur in the secondary market each year, the costs of implementing the universal background check are lower. Ironically they have helped make a stronger case for the new law. It would be cheaper if it only affected, say, 20 percent of the transactions, than if it affected 40 percent.”