The presence of a heavy truck on the road can impose an externality if accidents occur that would not have otherwise. We find each additional truck on the road increases the risk of a truck accident – but also, at an even higher rate, the risk of a car-on-car collision. Our estimates imply two...

As recent hurricane seasons have made clear, flooding can cause a great deal of property damage and human suffering. Indeed, flooding causes the most damage of any natural disaster in the United States and worldwide and affects the greatest number of people. Yet today most households are...