Back in 2009 I took the WSJ to task for a mendacious editorial claiming that increased CAFE fuel-efficiency standards would kill people by encouraging lighter cars. I pointed out that the most common heavy vehicles today, SUVs, have only a marginally lower total fatality rate than sub-compact cars, and are significantly more dangerous to their occupants than midsize cars. (Midsized SUVs have a 40% higher total occupant fatility rate than midsized cars!)
What really made and still makes me angry is the selfish mindset of SUV drivers who buy one because it's "safer for their family." It simply isn't safer overall for your family, and it's only less likely to kill you relative to the occupants of smaller cars in a multicar collision. The occupants of those vehicles (and pedestrians and bikers) hit by SUVs die at much higher rates. I'm updating this blog post because the NBER has recently come out with research to quantify that externality using the latest data available. They find that, "controlling for own-vehicle weight, being hit by a vehicle that is 1,000 pounds heavier results in a 47% increase in the baseline fatality probability. Estimation results further suggest that the fatality risk is even higher if the striking vehicle is a light truck (SUV, pickup truck, or minivan)."
So, contra the WSJ, the authors argue that to make the roads safer, we should increase the cost of fuel to discourage heavier vehicles and, "that the total fatality externality is roughly equivalent to a gas tax of $1.08 per gallon." It's probably even higher than that, because the paper doesn't attempt to account for the fact that SUVs are more likely to get into accidents than cars due to factors such as increased breaking distance, handling characteristics and driver overconfidence in poor road conditions.
So, don't buy an SUV for safety, and don't buy it when someone tells you that a US auto fleet with smaller cars will be more dangerous.