Anup Malani, "The Externalities of Vaccination on the Evolution of Influenza"
Getting a flu shot has private benefits (you won’t get sick) and social benefits (there will be less flu passed around). Anup Malani shares research that shows that vaccination can limit the virus’s evolution. This means that the social benefits may be even greater, but it increases the free rider problem. If more people are vaccinated, reducing both the incidence and evolution of flu, there is less need for an individual to get vaccinated.