Jessica
This is a very interesting example! There's a real challenge here because many people oppose extensive investment in charter schools because they fear it takes money directly away from the regular public school system. If this is so, the policy may help the direct beneficiaries but harm others in the community and ultimately exacerbate disparities. I do not know of any empirical evidence on this question of whether charter school investments weaken neighborhood public schools (or perhaps they strengthen them), though there may be work.
The question of whether charter school attendance helps the individual students is a little easier because many charter schools are over-subscribed. Children in Massachusetts (and other states, but I don't know if this is a federal policy) who apply to charter school are selected by lottery. As a result, there are some quite compelling studies of the effects of charter school attendance on children's educational outcomes. As far as I know, there have been no follow-ups to evaluate the impacts on children's health, although it's clearly a great opportunity. The first generation of kids who went to charter schools are probably now old enough to be having their own kids and developing chronic conditions, etc. Would be great to know if the outcomes are better or worse for kids randomly assigned to successful charter schools versus the kids who lost the lottery.
Maria