FIGURE 1.

Study subject flow chart. Prior to assigning purchase timing (single or multiple), we excluded sale records that were not for handguns, that were duplicate or invalid entries, or were missing key variables. Following purchase timing assignment, we excluded sales to other retailers, earlier sales of guns sold more than once in 1996, and all guns resold within 3 years after purchase. We identified 182,814 handguns; 136,185 (74.5%) acquired in single purchases and 46,629 (25.5%) in multiple purchases. Among the multiple purchase handguns, nearly half (21,686 guns, 46.5%) were bought on the same day with others. Among handguns not recovered by a law enforcement agency, we excluded those which had been purchased by a buyer who had also purchased a traced gun. We also excluded ATF traced handguns where the possessor of the weapon at the time of the trace was the purchaser of the gun. Our final sample was 180,321 handguns (86.1% of all handgun sales in 1996).