Community Effects: Measles Versus Eastern High

The outbreaks of measles have focused attention on community effects.  When a high percentage of the community has been vaccinated, there's herd immunity--the virus can't maintain itself.  So the choices made by individual families affect the whole community.

By chance the Post Sunday had a good article on the choice faced by a white family on Capitol Hill  Their teenage daughter was in an integrated DC intermediate school,but now is facing the decision of which high school to attend.  Does she go to Eastern, the local high school, almost entirely black (like the intermediate school) with known problems and the possibility it's on the upswing, or travel across town to a selective public high school.

On the one hand the daughter gets greater certainty of a good and challenging education with less risk of a bad experience; on the other hand she might be missing a unique experience and, more importantly, she contributes a bit to the community effect.

Recent research on upward mobility has shown the importance of community effects: the better the community by our customary standards (two-parent families, etc.) the better everyone does, particularly the poor. 

I'm not an anti-vaxer, but I think it's true a measles vaccination carries a risk, a very small risk, to the individual. But the risk to the individual is outweighed by the benefits to the community if everyone gets vaccinated, or at least in the neighborhood of 95+ percent.  So I've no problem in saying the individual should be vaccinated, and mandatory vaccination laws are good.  But why would I, and the liberal parents of the daughter in the Post article, hesitate to require her to attend her neighborhood school?  I think the answer is the probable cost to the individual is much higher and the probable benefit to the community, in the absence of many others in the same situation is minimal, meaning the tradeoff is unfair.

While that calculus seems to be convincing, it leaves the $64,000 question of how do we get positive community effects: how do you get a herd, a crowd, all moving in the same positive direction?