Self protection also depends on the prevalence Prevalence:proportion of a population that has a given disease Prevalence elasticity of less disease () (2) demand for self protection: measure of how demand for self protection responds to changes more protection less protection in the prevalence of that disease When a disease becomes more more disease widespread,people will go to greater lengths to avoid it. As we will see,this makes diseases harder to eradicate Bhattacharya,Hyde and Tu-HealthEconomics Bhattacharya, Hyde and Tu – Health Economics Self protection also depends on the prevalence  Prevalence: proportion of a population that has a given disease  Prevalence elasticity of demand for self protection: measure of how demand for self protection responds to changes in the prevalence of that disease  When a disease becomes more widespread, people will go to greater lengths to avoid it.  As we will see, this makes diseases harder to eradicate