In fact, said UGA statistics professor Mary C. Meyer, a new analysis of existing data indicates that, controlling for other factors, airbags are actually associated with slightly increased probability of death in accidents.
"NHTSA recorded 238 deaths due to airbags between 1990 and 2002, according to information about these deaths on their Web site," said Meyer. "They all occurred at very low speeds, with injuries that could not have been caused by anything else. But is it reasonable to conclude that airbags cause death only at very low speeds? It seems more likely that they also cause deaths at high speeds, but these are attributed to the crash.
"For any given crash at high speed, we can't know what would have happened if there had been no airbag; however, statistical models allow us to look at patterns in the data, and compare risks in populations, in a variety of situations."
The study was published this week in the magazine Chance.
The new analysis directly contradicts earlier studies about the effectiveness of airbags, which have been required for drivers and front-seat passengers in all cars since the 1998 model year in the United States.
While the value of airbags seems dubious in the new study, the value of seatbelts is not. The analysis found that proper use of a seatbelt reduces the odds of death by 67 percent for any given speed category and airbag availability. Airbags, however, cause no statistical difference in car-crash deaths, except for unseatbelted occupants at low speeds, where the odds of death are estimated to be more than four times higher with an airbag than without.