In response to a congressional request, GAO reviewed a Consumer Product Safety Commission (CPSC) staff memorandum containing comparative injury data for all-terrain vehicles (ATV), minibikes, and snowmobiles to determine: (1) the source and reliability of the vehicle usage data the memorandum presented; (2) whether its conclusions were justified; (3) why CPSC prepared it; and (4) whether its preparation was consistent with CPSC procedures.

GAO found that: (1) prior CPSC information indicated that ATV posed a greater consumer hazard than did minibikes and snowmobiles; (2) CPSC based this information on a comparative-injury analysis that did not consider the relative usage patterns of the three vehicles; (3) by contrast, the memorandum's comparative-injury analysis indicated that, based on an approximation of vehicle usage patterns, ATV posed no greater hazard to consumers than the other two vehicles; (4) the reliability of the memorandum's usage data was questionable because it was based on unsubstantiated anecdotal information from a small number of witnesses at CPSC public hearings on ATV; (5) CPSC officials believed that the earlier analysis incorrectly implied that ATV were more hazardous than minibikes and snowmobiles; (6) CPSC preparation of an adjusted analysis may have been inconsistent with the commissioners' intention to limit a staff analysis to ATV, as the other vehicles were not a regulatory concern at that time; and (7) CPSC restricted public dissemination of the memorandum pending further consideration.