Finding Love in the Wreckage: Estimating Spousal Altruism with Data on Fatal Car Accidents

This paper estimates the degree of altruism among spouses by examining how often the driver of a car sacrifices his or her own self in a car crash in order to save a spouse. Holding constant the magnitude of a collision, a driver can maneuver the car to distribute the risk from collision between the driver and a passenger. We quantify spousal altruism by the degree to which drivers riding with their spouse redistribute the risk from a fatal accident to themselves – as measured by ex post mortality – as compared to drivers not traveling with their spouse. We find that drivers with their spouses are roughly 1.21 times more likely to sacrifice themselves. Assuming a $10 million value of life, this implies a willingness to accept a $2,100,000 loss to avoid the death of a spouse. A driver faced with a possible collision will take evasive maneuvers. These evasive maneuvers have two effects: an allocative effect that reduces the magnitude of an impact for both occupants and a distributive effect that divides the remaining impact between the driver and passenger. If one could hold constant the allocative effect of the impact, then the distributive effect – to the extent that it can be manipulated by the driver – would reveal how the driver felt about the passenger. Conventional wisdom predicts that the driver riding with his spouse – due to his love for her – is more likely to sacrifice himself for the passenger. This paper uses revealed preferences to quantify how much people favor their spouses over others. We compare the distribution of mortality between driver and passenger when the driver is riding with his spouse to the distribution of mortality between driver and passenger when the driver is riding without her to estimate the level of the driver’s altruistic preference for his spouse. 1 University of Chicago Law School. Please send comments to [email protected]. We thank Edward Morrison for his comments. 2 To keep the prose simple, we use the male pronoun to describe the driver and the female to describe the passenger.