Smoke Detectors and Flawed Perceptions of Personal Risk with Tragic Results
A Washington, DC couple died following a fire in their multi-million dollar Dupont Circle townhouse earlier this week and it appears that they did not have a working smoke detector in the home. A few months ago, a wealth technology company executive died along with his wife and 3 small grandchildren in their 6,000 sq/ft Annapolis, MD mansion during a fire. While the home was valued at $6 million, there was not a working smoke detector in the residence. In both cases, a basic smoke detector would have likely provided ample warning to wake the residents so they could escape the fire without injury.
There is an interesting anomaly in risk perception and risk reduction when it comes to fire safety at home. The risk of fire death at a residence is twice as high in homes without a working smoke detector. In homes that had reported fires between 2007–2011, 27% of homes have no smoke detector and 48% had an inoperable smoke detector. Inoperable smoke detectors were almost exclusively caused by removed or dead batteries. A $3 investment in a new 9V battery can significantly reduce someone’s risk of dying in their home but millions of people don’t make that investment in risk reduction!
The inverse of the failed investment in smoke detectors is also occurring in Maryland because automatic sprinkler systems have been required by state law in all new residential construction including single family homes. Sprinklers are fairly common in high-rise and multi-family dwellings but rarely required in single family homes across the country. (http://www.firesprinklerinitiative.org/legislation/sprinkler-requirements-by-state.aspx). Residential sprinklers cost approximately $1.35 per sq/ft or $6,000 for an average single family home. A NIST study showed that sprinklers alone reduce fire death risk by 69% and sprinkler + working smoke detectors reduce risk by 82%. A smoke detector alone reduces risk by 63% without the sprinklers.
A $6,000 investment provides 19% less fire death risk and is legally mandated while a $3 investment in a smoke detector battery isn’t made in half of homes where fires occur. Greatest risk reduction/dollar doesn’t match legal requirements or personal investments! When we look at all of the investments that are made at the national level with infrastructure to make very small reductions in risk, it is amazing that smoke detector batteries can have such a huge impact for a minimal cost.
What is the reason for this problem with self-assessment of risk?
There has been a lot of writing about the optimism bias and personal risk analysis related to smoking.
The optimism bias is a tendency for people to believe that they are less likely to experience a negative event compared to others. For example, we acknowledge the danger of driving a car but believe that others are more likely to get in accidents (“people who get in car accidents are bad drivers, I’m a good driver!”). Similarly, studies consistently find that smokers believe the health risks of smoking are lower for themselves than for other smokers. Compared with nonsmokers, both adolescent and adult smokers significantly demote health risks from smoking.
The optimism bias is also linked to pre-disaster personal preparedness and post-disaster mitigation actions. People generally agree that preparedness is important for other people to do but under-perceive their own risk of experiencing a disaster. In the case of residential fire risk, it is likely that people under-perceive their own risk to the point that they don’t even invest $10 in smoke detector for their multi-million dollar home.
