An exploration of the offset hypothesis using disaggregate data: The case of airbags and antilock brakes

The offset hypothesis predicts consumers adapt to innovations that improve safety by becoming less vigilant about safety. Previous tests have used aggregate data that may confound the effect of a safety policy with those consumers who are most affected by it. We test the hypothesis using disaggregate data to analyze the effects of airbags and antilock brakes on automobile safety. We find that safety-conscious drivers are more likely than other drivers to acquire airbags and antilock brakes but these safety devices do not have a significant effect on collisions or injuries, suggesting drivers trade off enhanced safety for speedier trips.