Self-protection and insurance with interdependencies

"We study optimal investment in self-protection of insured individuals when they face interdependencies in the form of potential contamination from others. If individuals cannot coordinate their actions, then the positive externality of investing in self-protection implies that, in equilibrium, individuals underinvest in self-protection. Limiting insurance coverage through deductibles can partially internalize this externality and thereby improve individual and social welfare"--National Bureau of Economic Research web site.